jfcfi 
 
 
 
 ARY 
 
 REESE- LffiRAR 
 
 UNIVERSITY Q-F CA 
 
 Accessions No. <t 
 
 ' * Shelf "/ 
 
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COLLOTYPE 
 
 AND 
 
 PHOTO-LITHOGRAPHY 
 
 PRACTICALLY ELABORATED BY 
 
 DR. JULIUS SCHNAUSS, 
 
 Member of the Imperial German Academy of Naturalists, &c. 
 TRANSLATED, WITH THE AUTHOR'S SANCTION AND ASSISTANCE, 
 
 EDWIN C. MIDDLETON. 
 
 TOGETHER WITH AN APPENDIX ON 
 
 STEAM PRESSES, 
 
 BY THE TRANSLATOR. 
 
 LONDON : 
 ILIFFE AND SON, 3, ST. BRIDE STREET, LUDGATE CIRCUS. 
 
 1889. 
 
PRINTED BY ILIFFE AND SON, 3, ST. BRIDE STREET, LUDGATE CIRCUS, LONDON, E.C. 
 WORKS : COVENTRY. 
 
CONTENTS. 
 
 I. Introductory - 
 
 II. Bichromates in Conjunction with Organic 
 Substances - 
 
 III. Summary of the more important Printing 
 
 Processes with Chromated Gelatine - 
 
 IV. Collotype Apparatus - 
 
 V. Chemicals and Materials for Collotype 
 
 VI. Preparation of the Collotype Plate 
 
 VII. Negatives suitable for Collotype 
 
 VIII. Printing in the Press - 
 
 IX. Finishing and Varnishing Collotype Prints 
 
 X. Other Collotype Processes - 
 
 XI. Failures in Collotype: In the Preparation of 
 the Plates - 
 
 XII. Investigations on Collotype 
 
 XIII. Collotype in Natural Colours - 
 
 XIV. Magic Prints 
 
 XV. Photo " Glass" Printing - 
 
 XVI. Allgeyer's Collotype Process 
 
 XVII. Practice of Photo- Lithography 
 
 XVIII. Autography 
 
 XIX. Negatives for Photo-Lithography - 
 
 XX. Application of the Carbon Process to Photo- 
 Lithography - ... 
 
 PAGE. 
 
 9 
 
 12 
 
 18 
 
 25 
 
 46 
 
 59 
 72 
 
 88 
 96 
 
 102 
 
 I0 7 
 114 
 II 9 
 122 
 I2 4 
 127 
 I 3 
 
 !35 
 
 149 
 
 APPENDIX. 
 
 $tearn Presses - 
 
 162 
 
TRANSLATOR'S PREFACE. 
 
 THE impossibility .of obtaining any work in the 
 English language on the subject of Collotype 
 first led to my translation of the German work of 
 Dr. Schnauss, and the fact that no work has hitherto 
 appeared fully dealing with the matter is the excuse 
 I offer for the present publication. The translation 
 is necessarily one of considerable freedom, but it is 
 offered as containing all the information to be found 
 in the original, and in addition, considerable ex- 
 tensions, made with the author's consent. The 
 omission of the chapter dealing at length with the 
 steam machine was necessitated by the fact that 
 the rotary machine there described is no longer 
 manufactured. 
 
 Without pointing to the frontispiece in any 
 sense as a high-class work, it may serve to show 
 that I have made some practical acquaintance with 
 the subject. The illustration, printed on ordinary 
 paper, was produced from the instructions found in 
 this work, and I may add that at the time of writing 
 I have printed over 500 impressions from the first 
 plate, and it still remains in fair working condition. 
 
 EDWIN C. MIDDLETON. 
 
 STANMORE ROAD, 
 
 BIRMINGHAM. 
 
COLLOTYPE AND PHOTO-LITHOGRAPHY. 
 
 CHAPTER I. 
 
 INTRODUCTORY. 
 
 THE observation by Mungo Ponton of the sensi- 
 tiveness to light of bichromate of potassium 
 in conjunction with organic substances is but little 
 more recent than the discovery of photography itself. 
 if sized paper is saturated with an aqueous solution 
 of this salt and then exposed under any transparent 
 design, the latter will be reproduced as a negative of 
 a brown colour on a yellow ground. If the exposed 
 paper is placed in water, the bichromate salt will be 
 removed from the unexposed, and consequently un- 
 altered portions ; the image will remain brown 
 after this treatment, though somewhat bleached. 
 The sensitiveness to light is proportionately in- 
 creased by the addition of larger quantities of 
 organic substances, as starch, paste, glue, sugar or 
 gum, as first observed by Becquerel. This arises in 
 consequence of the organic matter being oxidised by 
 the chromic acid, a corresponding decomposition 
 and reduction of the chromate salt to chromate of 
 chromium taking place. 
 
 In the year 1853 an Englishman Fox-Talbot, 
 the gifted discoverer of calotype (i.e., the production 
 of photographic negatives on paper by means of 
 
 B 
 
io Collotype and Photo-Lithography. 
 
 silver salts) followed up the lines of these important 
 observations, and discovered that the mixture of 
 bichromate of potassium and glue entirely lost its 
 solubility and power of swelling in cold water after 
 exposure to light, and on this he based his process 
 (heliography) of etching on metal plates. The 
 plate, after receiving a coating of the chromated 
 gelatine solution, was dried, exposed under a posi- 
 tive, and afterwards developed or washed out in 
 warm water, all unexposed and consequently soluble 
 portions being removed, while the exposed and 
 therefore insoluble portions covered as a negative" 
 the metal plate, and so protected it in those parts from 
 the etching mordant employed, usually chloride of 
 potassium or perchloride of iron. His successor in 
 these researches was a Frenchman, Poitevin, who 
 invested these processes with even greater practical 
 importance. He, however, worked chiefly on paper 
 with the bichromate mixed with albumen or gelatine, 
 and attained results which were the first practical 
 steps towards photo-lithography and carbon or 
 pigment printing. Further on we shall return 
 with more detail to these subjects. In the hands 
 of Tessie du Motay and Marechal, of Metz, the 
 di-scoveries of Poitevin derived further practical 
 value, and to them we are indebted for the 
 first advances in collotype, they in their practice 
 using metal plates as a support. Joseph Albert, 
 
 For the production of an intaglio plate the impression on the 
 chromated gelatine must be printed from a positive, which will naturally 
 give a negative on the copper plate. 
 
Collotype and Photo-Lithography. 1 1 
 
 of Munich, followed, and introduced further and 
 considerable modifications, amongst others utilising 
 glass plates as a foundation. The want of adhesive- 
 ness of the chromated gelatine layer to its support 
 was a source of great trouble to the earlier experi- 
 mentalists, and was a matter giving rise to innumer- 
 able difficulties, which were, however, finally 
 surmounted by the researches of Husnik, Albert, 
 and Obernetter. 
 
12 Collotype and Photo-Lithography. 
 
 CHAPTER II. 
 
 THE BICHROMATES IN CONJUNCTION WITH ORGANIC 
 SUBSTANCES. 
 
 HROMIC Acid, now usually known as chro- 
 mium-trioxide CrCX is found in beautiful red 
 needles, which are slightly deliquescent. According 
 to the present accepted theory, water containing 
 such crystals in solution contains the true chromic 
 acid, H 2 CrO 4 , which cannot be produced as 
 crystals. Both the crystals and a concentrated 
 solution in water give up with facility a part of their 
 oxygen, sometimes with explosions accompanied by 
 the appearance of fire, and green chromium oxide, 
 now called sesquioxide, Cr 2 O 3 , is formed. Bichro- 
 mates of alkalies act in a similar manner, but in a 
 lesser degree. If, for instance, a few drops of sul- 
 phuric acid be added to a solution of potassium 
 bichromate, and then a little alcohol, or, instead of 
 that, a piece of sugar be added and moderate heat 
 applied, the solution will be violently agitated, its 
 yellow-red colour will disappear, the bichromate be 
 decomposed, and chromium oxide be formed, which, 
 combining with the sulphuric acid, forms a solution 
 of a violet green colour. If a sufficient quantity of 
 sulphuric acid be present, the chromium sulphate 
 and the potassium sulphate combine, forming chrome 
 
Collotype and Photo -Lithography. 13 
 
 alum crystals, octahedron in form, similar to those of 
 ordinary alum, but of a beautiful dark violet colour. 
 The same are used in both the carbon and collotype 
 processes. Bichromate of ammonium is easily 
 decomposed by fire by heating it in a dry state. It 
 will be understood that in consequence of the decom- 
 position, or rather reduction, of chromic acid by 
 organic matter, the latter is also decomposed and 
 oxidised in a corresponding degree. The agent pro- 
 ducing this effect may be either heat or light, or both 
 together ; but of special interest to the collotypist is 
 the action of light upon different combinations of 
 chromic acid, in the shape of alkali bichromates in 
 conjunction with organic matters. 
 
 Glue or Gelatine, in a solution containing about 
 five per cent, of one of the bichromates spread upon 
 glass plates, and exposed to light, will, where exposed, 
 become dark brown, at the same time become 
 insoluble in water, and also lose its power of absorb- 
 ing the same. According to the researches of Dr. 
 Eder, this brown substance consists cf chromium 
 chromate and unaltered gelatine. The oxidised 
 portion of the latter remains soluble and may be 
 entirely removed by treating with warm water. 
 During the exposure to light formic acid is un 
 doubtedly formed. Ammonium bichromate, with 
 gelatine, is in the dry state much more sensitive 
 than the potassium salt ; it also decomposes more 
 readily when heated in the gelatine solution, a 
 matter which must not be lost sight of in the prepara- 
 tion of the collotype plate. 
 
14 Collotype and Photo-Lithography. 
 
 Isinglass a tolerably pure glutin. In con- 
 junction with the bichromates it presents the same 
 characteristics as gelatine. 
 
 Albumen, when mixed with a solution of a 
 bichromate, is not thereby coagulated, as occurs 
 upon the addition of pure chromic acid. If poured 
 upon glass and dried it also becomes insoluble 
 in water after a sufficient exposure to light. 
 This solution is used with great advantage in 
 photo-lithography, as the unexposed parts are readily 
 soluble in cold water. The older method, which 
 consisted of using gelatine in conjunction with 
 bichromate, rendered hot water necessary in the 
 development of the fatty ink image upon the transfer 
 paper, and as a consequence of the rubbing at times 
 necessary, the ink, already softened by the warm 
 water, became smeared, the resulting image con- 
 siderably impaired, and the transfer thereby rendered 
 altogether useless. In collotype a bichromated 
 albumen substratum is still used by many operators, 
 this coating when dry being exposed through the 
 glass plate, the latter placed coated side downwards 
 upon a flat black support, preferably of velvet. 
 After this exposure the gelatine layer from which 
 the prints are produced is applied. This method 
 was first published by Albert, who originated it. The 
 chromated albumen solution will not keep long even 
 in the dark,* as the albumen coagulates, and on this 
 
 *I have found this solution keep a considerable time a month at least. 
 TRANS. 
 
Collotype and Photo-Lithography. 15 
 
 account photo-lithographic papers coated with this 
 solution must be used within a few hours of their 
 preparation. Such papers are now conveniently 
 prepared with the albumen, * and sensitised as 
 required by floating upon an aqueous solution of 
 one of the bichromates, to which has been added 
 twenty-five per cent, of methylated spirit. 
 
 The chromated gelatine used in collotype may 
 be kept as a jelly in the dark room, but is better 
 prepared fresh. 
 
 Of carbon hydrates only gum chromate is of 
 interest to the collotypist, its employment being 
 restricted to the " dusting on" process, and the occa- 
 sional addition of titles, &c., to the otherwise finished 
 plate. As with all mixtures of the bichromates and 
 organic substances, it is only sensitive to light when in 
 a dry condition, and solutions of it may, without harm, 
 be exposed for some time to diffused daylight. Aqueous 
 solutions of gum arabic soon become sour and 
 mouldy, and in this condition are useless for the 
 " dusting on," or, in fact, any other photographic 
 process. As a preventive a few grains of sulphate 
 of quinine may be added, which will preserve it 
 effectually, and is quite inert in photographic opera- 
 tions. 
 
 This solution applied to glass and dried is, in its 
 dry condition, extremely sensitive to light. If 
 printed under a negative, and then exposed to a 
 
 *I believe Husnik has now discontinued to prepare his photo-litho 
 transfer paper with an albumen coating. Recent issues of his paper have been 
 simply coated with gelatine. TRANS. 
 
1 6 Collotype and Photo-Lithography. 
 
 damp atmosphere, it absorbs moisture, and becomes 
 " tacky" upon the portions fully protected by the 
 densest portions of the negative, while the parts 
 exposed under the clear glass of the negative will be 
 free from any such tendency. The gradations of 
 the negative between these two extremes will be 
 represented by the surface of the gum being more or 
 less adhesive, and it is this property which renders it 
 valuable in various processes. After exposure under 
 a negative, finely-ground colour for instance, graphite 
 is carefully dusted over the surface of the plate by 
 means of a camel-hair brush, and the powder will 
 adhere in exact proportion to the protection afforded 
 by the negative. A picture is thus produced in 
 graphite powder possessing all the gradations of the 
 original. From a negative a second negative is 
 produced, while from an exposure under a positive a 
 positive will result, each, however, reversed as 
 regards left and right when compared with the 
 original. Advantage is taken of this process to 
 produce reversed negatives, a subject more fully 
 dealt with in another chapter. 
 
 Bichromate and Sugar are never used alone, 
 but as an addition to heighten the sensitiveness and 
 increase the hygroscopic properties of the gelatine or 
 gum-chromate solutions. By the addition of sugar 
 and a little ammonia to chromated gelatine the 
 solubility of the gelatine in hot water is increased. 
 The addition of acetic acid instead of ammonia acts 
 in a contrary direction. It is advisable to become 
 acquainted with the action of certain substances, the 
 
Collotype and Photo -Lithography. 17 
 
 application of which to the printed layer increases 
 its solubility after exposure to light, and of others 
 having a contrary or hardening influence on the 
 same, such oft-times proving of service in the case 
 of under or over exposure. To the former class 
 belong all alkalies, as chloride of lime and cyanide 
 of potassium ; while among the latter, which have a 
 tanning or hardening effect on gelatine, may be 
 particularly mentioned tannin, alum, chrome alum, 
 and chloride of zinc. 
 
 To remove spots, which print dark, from 
 collotype plates a solution of chloride of lime is used. 
 To produce dark spots without exposure to light a 
 solution of tannin is used, which is also available for 
 adding descriptive titles or other matter to the 
 plates. The ink will " take" as well on the spots or 
 parts touched with the tannin solution as if exposed 
 to light. A collotype plate which has been prepared 
 for printing from may also have writing executed 
 upon it with a bichromated gum solution, once more 
 exposed to light, the writing will then readily take 
 the ink, and appear in the impression as a black 
 inscription. 
 
 Gum chromated solutions reduced to proper 
 proportions, and applied to different textures and the 
 same subsequently exposed to the light, render 
 them completely waterproof. 
 
1 8 Collotype and Photo-Lithography. 
 
 CHAPTER III. 
 
 SUMMARY OF THE MORE IMPORTANT PRINTING 
 PROCESSES WITH CHROMATED GELATINE. 
 
 THESE processes are all based upon the change 
 in the hygroscopic properties of chromatecl 
 gelatine brought about by the action of light, 
 which renders the parts exposed insoluble. 
 
 Carbon or Pigment Printing. In this in- 
 teresting process finely ground colouring matter is 
 added to the solution of chromated gelatine, and 
 spread upon paper ; or the paper may be coated 
 with the gelatine and pigment, and afterwards 
 excited by immersion in a solution or bath of one of 
 the bichromates. If, after drying such paper or 
 tissue, it be exposed under a negative in an ordinary 
 printing frame, and then immersed in warm water 
 (90 to 130 F.), the water will dissolve only such 
 portions as may not have been affected or hardened 
 by the action of light through the negative, while the 
 parts that have been exposed to its action will be 
 insoluble, and remain attached to the paper support, 
 forming a positive picture. Images produced in 
 such a manner, however, are devoid of half-tone, and 
 this procedure is only suitable for line subjects, while 
 even for such the paper must have been very evenly 
 
Collotype and Pkotd-Litko#mphy. 19 
 
 coated, or portions of the picture may be washed 
 away. For the production of half-tone subjects it is 
 necessary that the picture be developed from the back. 
 This may be effected by transferring the printed 
 tissue, after first soaking in cold water, to a surface, 
 usually either of paper or glass, and developing it in 
 contact with, and allowing it to remain upon, such 
 surface. Th's procedure is known in carbon printing 
 as single transfer. Unless the negative be a reversed 
 one or a film printed from the reverse side the 
 resulting print will be subject to the disadvantage of 
 being reversed as regards left and right. In cases 
 where ordinary negatives have to be used, and this 
 reversal cannot be tolerated, it is overcome by the 
 "double transfer" method of printing, the print in 
 such cases being developed upon a so-called " tempo- 
 rary support," and again transferred to its " final 
 support," when it appears as a non-reversed image 
 in permanent pigment." 
 
 The " Powder " Process. Take, instead of 
 gelatine, a solution of gum arabic and sugar, to 
 which is added a solution of bichromate of potassium 
 or ammonium. With this a glass plate is coated, 
 dried, and exposed under a negative, if it be desired 
 to produce a negative; or, if a positive be desired, 
 the exposure must be made under a positive. After 
 a short exposure the plate is dusted over with a 
 powder in an extremely fine state of division, such as 
 graphite if for negatives ; if for burnt-in enamels, a 
 
 *For further details of this interesting process see the " Autotype 
 Manual," by J. R. Sawyer; or Liesegang's "Carbon Process.' 
 
2O Collotype and Photo-Lithography. 
 
 specially-prepared enamel, ground extremely fine, 
 must be used. Such powders will only adhere to the 
 plate in exact proportion to the action of the light 
 during the exposure in the printing frame, and a 
 reversed copy of the original will be produced. 
 
 Collotype and Glasstype.* In these pro- 
 cesses the printing depends upon the property 
 possessed by the bichromated gelatine film, which 
 has been properly exposed under a negative, of 
 absorbing water in varying proportions, in exact 
 accord with, but in inverse ratio to, the action of the 
 light. The application of a roller charged with 
 fatty ink of a suitable consistency, will deposit upon 
 the gelatine surface a layer of ink in exact proportion 
 to the action of the light and in inverse proportion 
 to the amount of water absorbed by the film. In 
 this manner a picture is produced in ink which by 
 printing is transferred to paper, and will exhibit all 
 even the finest gradations of light and shade. 
 
 Woodburytype. If an especially thick film of 
 gelatine, containing a small proportion of pigment, 
 be sensitised, exposed under a negative, and sub- 
 jected to prolonged soaking in warm water, a picture 
 exhibiting considerable relief will be obtained, which, 
 after drying, may, by pressing into lead or treated 
 by the galvanoplastic method, yield a matrix from 
 which casts may be produced in a coloured gelatine 
 solution, or ink, which is poured into the mould ; on 
 this is placed a waterproof paper ; the press, which is 
 
 'Glasstype, more fully described later on, has never been practised 
 commercially in England. 
 
Collotype and Photo-Lithography. 21 
 
 of special construction, is closed, and the ink allowed 
 to set ; the paper is then removed, bearing upon its 
 surface the printed Woodburytype, which is hardened 
 by alum, and then scarcely distinguishable from a 
 silver print. 
 
 Stannotype is a modification of the last-des- 
 cribed process by the same inventor. A positive is 
 first produced from the original negative, and from 
 the positive a print; is made on a thick gelatine 
 tissue. This is developed by long washing in warm 
 water, the resulting relief being a negative ; this is 
 coated with tinfoil of extreme thinness, and used as 
 a mould for printing from with the gelatine ink, as 
 previously described. This obviates the use of 
 hydraulic pressure and special and expensive appli- 
 ances. 
 
 Heliogravure ; Photogravure. If, instead of 
 printing from the Woodbury mould in the gelatinous 
 solution, a fatty ink is used, the process is known 
 under these titles. The exact methods of roughing 
 the depths of the plates to facilitate their retention 
 of the ink are regarded as secrets by the most 
 successful operators. 
 
 Photo-Lithography and Photo-Zincography. 
 In dealing with a subject in lines, dots, or stipple, 
 a paper may be coated with a solution of chromated 
 gelatine, dried, exposed under a suitable negative, 
 coated with a film of fatty ink, and allowed to soak 
 in cold or tepid water ; this, penetrating the un- 
 hardened portions of the film, causes them readily 
 to part with the ink, which, however, adheres. 
 
22 Collotype and Photo-Lithography. 
 
 tenaciously upon the hardened portions, representing 
 the picture. This image, when properly cleared, 
 may be transferred to stone or zinc, and printed from 
 in the lithographic manner upon a suitable press, or 
 if the image upon the zinc be etched into relief by 
 the process known as Gillotage, and mounted on a 
 -wood block of suitable height, it presents a printing 
 surface which maybe used in conjunction with type. 
 
 Gelatinotype. It has long been felt as a 
 desideratum to make use of the photogenic properties 
 of the gelatino-bichromate for letterpress printing, 
 i.e., to find out a simple and satisfactory method by 
 which collotype plates could be transformed in letter- 
 press printing plates. There have been made many 
 attempts in this direction, but hitherto without any 
 practical results ; the difficulties seemed to be too 
 great. Recently, however, Professor J. Husnik, of 
 Prague, has overcome these difficulties, his new 
 patented process, called by him u Leimtypie," that 
 is to say, Gelatinotype, being one of the greatest 
 practical value, quick, cheap, and giving most satis- 
 factory results. The process consists in the pro- 
 duction of high relief blocks in gelatine. Husnik 
 exposes a gelatino-bichromate tissue under a negative, 
 and then develops the relief picture in a peculiar 
 mariner. 
 
 The method consists in the application 01 a 
 saturated solution of bichromate salts for developing, 
 a new and previously unknown property of the chrome 
 salts thus coming into employment. These salts, in 
 comparison with the acids, have the advantage not 
 
Collotype and Photo- Lithography. 23 
 
 only of dissolving all unexposed gelatine during de- 
 velopment, but also in hardening the already exposed 
 parts of the picture upon the copy to be developed, the 
 impression received from the light being increased by 
 contact with the chrome salt solutions. In this 
 way the relief can be developed a longer time, and 
 becomes deeper. 
 
 Another new phase is the manner of the second 
 development. The first development is interrupted 
 before the fine parts have been injured, the relief 
 allowed to dry, the white parts (the sub-ground) 
 covered with printing ink diluted with turpentine, 
 using a fine brush quite near to the lines, and then 
 the whole relief exposed once more to light. The 
 relief, on account of its having taken up much chrome 
 salt during the first development, is very sensitive to 
 light, and hardens not only on the surface, but also 
 on the sides of the lines. Alter removal of the black 
 ink it can be developed to any depth, particularly if 
 the larger white parts have before been cut out with 
 a knife. 
 
 This process has lately been further improved 
 by the inventor, by the use of gutta-percha films, 
 which are placed between the gelatine film and the 
 zinc plate on which the gelatine relief has to be 
 fastened. This is effected as follows : The zinc 
 plate, after having been well cleaned and rubbed over 
 with emery paper, is coated with a gutta-percha 
 solution and dried. It is then heated to about 
 212 F., and allowed to cool. During this cooling 
 process the bichromated gelatine film, before being 
 
24 Collotype and Photo-Lithography. 
 
 developed, is laid on at a temperature of between m 
 and 77 F., whereby the hardening gutta-percha film 
 secures a perfect combination with the zinc plate. 
 When this has been done the gelatine film is developed 
 in the above described manner to a relief. By this 
 improvement the gelatine blocks become so solid that 
 they will yield more than 50,000 prints in the print- 
 ing machine without being injured. 
 
Collotype and Photo-Lithography. 25 
 
 CHAPTER IV. 
 
 COLLOTYPE. APPARATUS. 
 
 BEFORE commencing any practical work it will, of 
 course, be necessary to procure various utensils 
 and material not usually found in the photographic 
 studio. All these should be procured from reliable 
 dealers and of the best quality, for the evil conse- 
 quences of false economy will make themselves felt in 
 endless failures. The best to be obtained are none too 
 good for collotype. In the practice of photography the 
 whole success depends on a series of apparent trifles, 
 and the same may be said to hold good, but in a far 
 greater degree, in this process, which is one in which 
 the difficulties can scarcely be overestimated. 
 
 The photographer will most likely be already in 
 possession of many pieces of apparatus he may utilise 
 for instance, dishes. The best and dearest are those 
 of china ; but for many in fact, most collotype 
 purposes, those of tin or zinc may be used. 
 
 For warming or cooking the gelatine solutions 
 tin vessels are the handiest, as they easily conduct 
 the heat and are unbreakable. Although the chro- 
 mated gelatine may remain in them for a short period 
 without harm, it is not advisable to allow it to do so 
 for any length of time, but to remove the solution and 
 wash the vessel thoroughly with hot water, and at 
 
26 Collotype and Photo-Lithography. 
 
 once carefully dry, otherwise they will soon corrode, 
 and contaminate the gelatine solutions. The best 
 utensils to use are wide-mouthed shallow jugs, 
 as they are easily kept clean, and in them the 
 chromated gelatine solution keeps well, and with their 
 use no fear of decomposition need be entertained. 
 
 Filtering the gelatine solutions is a somewhat 
 troublesome matter, and should be effected at a high 
 temperature and as quickly as possible. The 
 simplest method is to procure a piece of perfectly 
 clean flannel of suitable size, thoroughly moisten it, 
 and insert into a brass ring, which is provided on 
 the outside with small barbel hooks, to which the 
 flannel is fixed, as in the retinaculum of the 
 chemist. The ring is provided with a clip and 
 handle, by the former of which it may be attached 
 to a vessel of almost any size, and the latter is a con- 
 venience in holding it over plates to which the gelatine 
 has to be applied. A careful filtering is obviously 
 essential to the production of clean plates. Many 
 complicated filtering appliances have been devised for 
 gelatine and other solutions difficult of filtration, as, for 
 instance, those of albumen or gum. Baron Szretter 
 describes in the " Photographische Correspondenz," 
 1878, an apparatus constructed by him. It consists 
 of two vessels, an upper and a lower one, which by 
 means of longer or shorter tubes communicate with 
 each other in accordance to the stronger or weaker 
 pressure required by the liquid to be filtered. 
 Soldered round the upper rim of the lower vessel is a 
 ring of sheet brass, about two to three in cm. width ;. 
 
Collotype and Photo-Lithography. 
 
 27 
 
 over this ring the filter paper is placed, which 
 again is covered with a piece of strong felt 
 enveloped in flannel. To prevent the liquid escaping 
 round the sides of the ring a strong iron ring is 
 applied, which by means of a screw presses against 
 the felt so that no space exists between the ring and 
 the paper. To prevent the pressure of the liquid 
 forcing the felt out of position, and so tearing the 
 paper, a metal wire gauge is used to keep the felt in 
 place. The liquid placed in the upper vessel passes 
 through the tube into the lower vessel through the 
 paper and felt layer. When it is necessary to warm 
 the solution to be filtered, as in the case of gelatine, 
 the whole apparatus is covered with an outer cover- 
 ing, and on the other side a pipe is applied for the 
 purpose of effecting a circulation of the heated 
 liquid, which is thus kept constantly rising through 
 the one pipe and returning through the other.* 
 
 Fig. i. 
 
 *The above description not perhaps being perfectly clear, and having been 
 unable to obtain any further description, I give a sketch (Fig. r .) of an apparatus 
 found to answer well for the filtration of gelatine solutions and other viscid 
 bodies. A is a glass flask, B a rubber stopper, C a funnel containing a 
 filtering medium of washleather, D a tube attached to a three-way cock E 
 one hand manipulates the latter, while the other works the piston F of a 
 syringe G. TRANS. 
 
28 Collotype and Photo-Lithography. 
 
 Heat is sustained at an even temperature during the 
 whole operation by means of a small lamp. A 
 simple method of filtering such solutions is to pass 
 them through purified sheep's wool, or spun glass, a 
 quantity of which is placed in the tube of the funnel. 
 The whole apparatus may be placed in a warm oven 
 during the process, or the drying box may be 
 utilised for the purpose. 
 
 Printing Frames of different sizes will be 
 found to hand in the photographic studio, and may 
 be utilised without alteration for printing the 
 collotype plates, if they are deep and strong enough 
 to bear the necessary pressure, which is usually 
 applied through the medium of springs; these are 
 better removed, and wooden wedges inserted in their 
 stead between the cross-bars and the loose wooden 
 back of the frames, as by these means far more pres- 
 sure may be applied. By lifting the one half of the 
 hinged back of the printing frame an examination by 
 transmitted light of the collotype plate may be made 
 and an experienced operator will in this manner 
 judge the exposure of the plate. 
 
 The Actinometer is, however, recommended, 
 particularly for a beginner, as it greatly aids in 
 forming a correct idea of the exposure. 
 
 The Drying Box is of great importance to the 
 successful working of the process. The opinions of the 
 various practitioners with regard to the temperature 
 at which the drying cf the plates should be 
 effected differ as widely as upon the advisability or 
 
Collotype and Photo-Lithography. 29 
 
 otherwise of admitting a current of air through the 
 box during the operation. The drying should 
 be completed as rapidly as possible from the 
 commencement of the operation, care being taken 
 that the heat never exceeds 5oC. Many plate- 
 makers simply dry the plates in an open apartment 
 of course, only illuminated by a non-actinic light 
 simply placing the plates on a horizontal surface, 
 which may be maintained at the temperature in- 
 dicated by a water bath, a lithographic stone, or 
 merely a cast-iron plate arranged in a suitable 
 manner for heating from below. This method of 
 drying is open to many objections : the surface of 
 the plate is seldom free from dust, and the gelatine 
 coating is too liable to irregularities from draughts 
 admitted to the apartment during the process. They 
 are more frequently dried in specially-constructed 
 boxes provided with screws for accurately levelling 
 the plates, and through which only a small circula- 
 tion of air takes place. These boxes are usually 
 rectangular in shape, the upright sides being of 
 wood and the bottom of sheet iron. The lid is an 
 open framework covered with a close orange or black 
 cotton material, the whole standing upon four iron 
 legs over a spirit or gas flame. In the upper part of 
 the box a thermometer is fixed, about the centre of 
 either the side or lid, in such a position that it may 
 be readily observed without the necessity of opening 
 the box. Strong horizontal iron bars are placed 
 across at about the centre, and are provided with 
 
Collotype and Photo-Lithography. 
 
 thumbscrews, upon which may be placed a plate of 
 glass bearing a circular spirit level, by which means 
 the plates may be levelled with the greatest accuracy. 
 The sheet-iron bottom of the box being heated 
 unevenly, it becomes necessary to mitigate this 
 inconvenience as far as possible, which is easily done 
 by covering the plate to a depth of about half-an-inch 
 with dry river sand, over which should be placed 
 tissue paper to keep down any possible dust. 
 
 An Automatic Regulator of practical value is 
 that devised by Ruegheimer. It consists of a glass 
 tube, A, A 1 , A 2 . A 1 is closed with an indiarubber 
 
 H 
 
 Fig. 2. 
 
 stopper, through which passes a glass tube B, the 
 lower end of which is cut off at an angle. It is 
 attached to the gas supply pipe. The tube C is 
 connected to the burners. To D is attached, by 
 means of rubber tubing, a glass bulb F, which is 
 placed inside the drying-box. G G is mercury, and 
 H a rubber stopper by which the pressure on the 
 mercury and quntiaty of air in F may be regulated. 
 
Collotype and Photo-Lithography. 
 
 The action of the instrument is obvious. The gas 
 passes down B, over the surface of the mercury and 
 by the tube C to the burner. On the bulb F reaching 
 a certain temperature, the mercury will allow just 
 sufficient gas to pass from the tube B to maintain the 
 box at a given heat. If it should fall, the mercury 
 recedes from the aperture of the tube B, a larger 
 quantity of gas passes to the burner, and the 
 temperature is restored to a normal degree. If the 
 air in the ball F expands to too great an extent, the 
 mercury rises, and would eventually entirely close 
 the aperture and cut off the gas supply, unless 
 the tube B is provided with a small hole acting 
 as a by-pass. The tube B may be moved up and 
 down through the rubber stopper at A 1 as a means 
 of adjustment. 
 
 M. Thiel, of Paris, uses a very convenient 
 drying-box, which, with his permission, is here ex- 
 plained. In a brick-lined receptacle under the 
 laboratory floor lies the water-heating apparatus, 
 which is constructed of sheet copper, and is capable 
 of containing about four litres of water, utilised in 
 
 Fig. 3- 
 
 the production of steam for heating the box. a, fig. 
 3, is the pipe passing through the wall into the 
 
Collotype and Photo-Lithography. 
 
 drying-box ; b is the gas supply pipe to the two 
 atmospheric burners. Fig. 4 represents a plan of the 
 
 / d d d 
 
 d 
 
 Fig. 4. 
 
 drying-box ; c c c c the perpendicular sides of the 
 same, a a a gives a plan and position and arrange- 
 ment of the earthenware heating pipes lying in a 
 serpentine form at the bottom of the box, entirely 
 covered with dry sand, and this again covered, as 
 before described, with tissue paper, b is the outlet 
 of the steam pipe, d d d d are movable horizontal 
 iron bars with adjusting screws, on which the plates 
 are levelled. The box is covered by a hinged lid, 
 which is raised about a couple of inches during the 
 drying to allow the air to circulate. The dimensions 
 of the box will be determined by the size of the 
 plates to be used, several of which may be placed 
 side by side. Its height is about half a metre inside, 
 and the plates are placed about its centre. 
 
 Glass Plates, to be used for printing from, 
 must as a first consideration have their surfaces 
 
Collotype and Photo-Lithography. 33 
 
 ground quite true and parallel. Since the introduc- 
 tion of special collotype presses requiring less 
 pressure, the thickness is of less consequence than 
 formerly, but for convenience of handling and to 
 withstand the necessary pressure, in the printing 
 frames, plates of at least four millimetres in thick- 
 ness are desirable. Many use them from 8 to 10 
 millimetres in thickness ; this, in the larger sizes, 
 means a weight both inconvenient and difficult to 
 handle. It is probably easier to work upon plain 
 glass surfaces, and since means have been discovered 
 of causing the chromated gelatine to adhere to 
 polished glass with sufficient tenacity to produce 
 several hundred impressions, the employment of 
 ground glass plates is much more a matter of choice 
 than formerly. The ground surface, however, assists 
 the formation of a grain in the case of thin layers, 
 and the operation of grinding serves to remove acci- 
 dental scratches from the surface of the plates. As 
 in practice these damages constantly arise, it will in 
 the long run be found both desirable and economical 
 to employ the ground plates. 
 
 Ink Rollers are also of great consequence in 
 both collotype and lithographic operations. For 
 printing from stone leather rollers have always been 
 exclusively employed, and they are still used in some 
 collotype establishments, more particularly where 
 hand presses are yet worked. 
 
 The Leather Roller consists of a wooden 
 cylinder or stock of about 21 to 42 cm. in length and 
 
34 Collotype and Photo-Lithography. 
 
 g to ii cm. in diameter, with handles at either end, 
 usually turned in one piece with the cylinder. Box- 
 wood handles are sometimes let into the ends of the 
 cylinder, but although smoother to work, they not 
 infrequently work loose. In using these rollers the 
 handles do not come in direct contact with the hands, 
 but are covered with a protection of stout leather, 
 which not only protects the printer's hands from 
 heating, but enables him by a heavier or lighter grip 
 of the handles to apply a heavier or lighter pressure 
 of the roller a point of great value in inking the 
 plate. 
 
 The wooden stock of the roller is first covered 
 with a double thickness of woollen material flannel 
 or Melton cloth and over this is drawn the cover of 
 calf-skin, flesh side outwards. The manipulation of 
 the seam must be managed with extreme care, as 
 any unevenness would render the roller useless. At 
 both ends of the cylinder the leather projects, and 
 is usually drawn tight with string or nailed on. 
 There are two descriptions of leather rollers smooth 
 and coarse. The latter are only used to apply ink 
 to the stone or plate, and then, with the smooth 
 roller, the proper distribution of the ink is effected. 
 For the latter purpose, in collotype, hard glue or 
 indiarubber rollers are employed, being considered 
 far preferable. When a leather roller is in good 
 order, and its use has been thoroughly mastered, it 
 is looked upon by many printers as indispensable. A 
 serious disadvantage is that when new they are 
 
Collotype and Photo-Lithography. 35 
 
 almost unusable for collotype, and after prolpn^fxf ' 
 
 use the leather stretches, they become wrinkled, x>\ 
 
 and this, of course, affects the even distribution *>' 
 
 Cy y/^ y 
 
 of the ink. A new leather roller needs a specia^g 
 preparation or " breaking in" before it may be con- 
 sidered fit for use. It should be well saturated with 
 a fatty matter, a very effectual way of doing which 
 is to roll it well at intervals in a moderate supply of 
 thin varnish as used for thinning printing ink, this 
 process being persevered with so long as the roller 
 continues capable of absorption. A better but more 
 troublesome method is to roll the rollers twice daily 
 in thin varnish, continuing the operation for a week, 
 at the end of which time the roller may be well rolled 
 upon the inking slab in stiff black printing ink, the 
 superfluous ink being occasionally removed from both 
 the roller and slab by scraping with a blunt knife, 
 and a fresh supply of ink applied. This troublesome 
 and tedious operation should be continued for a 
 period extending over several weeks until it has 
 become quite smooth and even, though it will still be 
 found better to use it only for common work, or, if 
 possible, on stone. To keep the roller in good con- 
 dition it should, on each occasion after use, ~be 
 carefully scraped with a clean, smooth-edged knife 
 not too sharp. Some practice in this operation is 
 required to avoid cutting the leather. Great care 
 should be taken to avoid this, the blade of the knife 
 being held almost flat upon the roller during the 
 process. The scraping should always be in one 
 
36 Collotype and Photo-Lithography. 
 
 direction, to ensure which it is advisable to place a 
 mark upon one of the handles. 
 
 Unless these precautions be observed the ink 
 will dry in, and completely spoil the leather. If not 
 to be used again for some time tallow should be 
 carefully and thoroughly rubbed into the surface of 
 the roller as a preservative, but before again using 
 this coating must be removed either by means of a 
 knife or washing with turpentine. 
 
 Glue Rollers have long been in use, but chiefly 
 for letterpress work and steam machines in general. 
 A soft composition of a very elastic nature is quite 
 useless for collotype ; its substance must, on the 
 contrary, be tolerably hard, and of a brown colour, as 
 usually employed on the steam letterpress jobbing 
 machines. For hand rollers for collotype it is pre- 
 ferable to have a strong iron frame with double 
 handles, as used by letterpress printers. Such rollers 
 are preferable to those of leather, and will answer 
 perfectly for laying on the first stiff ink, and also for 
 rolling up the half-tones. To clean they should on 
 no account be scraped, but simply washed with 
 turpentine, and on this account are much easier 
 cleaned than leather rollers. Schaarwachter gives 
 the following as an excellent composition for collo- 
 type rollers : Brown glue, three parts, steeped for two 
 days in cold water. The pieces should then be dried 
 in a cloth, and afterwards dissolved. When melted 
 add, with constant stirring, one part of treacle, which 
 has been previously boiled, allow the whole to boil, 
 
Collotype and Photo-Lithography. 37 
 
 and skim. The composition is then run into a thin 
 copper cylinder or mould, which must be polished 
 smooth, clean, and well oiled ; and in the centre of 
 which has been placed the wooden cylinder or stock. 
 After cooling, the roller is pushed out of the mould, and 
 washed with alcohol or turpentine to remove any 
 trace of greasiness due to oiling the mould, placed in 
 a bath of tannic acid, washed with water, and dried. 
 The composition rollers, as used in typographic 
 printing, are made with glycerine instead of treacle, 
 and may be used for collotype if not too soft. 
 
 Indiarubber Rollers are more expensive, but 
 possess special properties rendering them particularly 
 suitable for photo-lithography. In construction a 
 wooden stock with suitable handles is covered with 
 very thick well-vulcanised indiarubber, which has a 
 fine smooth surface, rendering it easy to clean by 
 means of turpentine. If it becomes " tacky 7 ' on 
 the surface it should be well rubbed with French 
 chalk, or soap-stone, which will readily absorb the 
 turpentine, but this coating must be thoroughly 
 removed before again using the roller. An excellent 
 suggestion appeared in one of the polytechnical 
 periodicals, that the rollers should before use be 
 coated with a solution of pure or bottle rubber in 
 benzole or bisulphide of carbon alter having been 
 well washed with turpentine. 
 
 These indiarubber rollers are not suited for the 
 first inking of the plate, but are invaluable for rolling 
 up the half-tints of the collotype plate. As they 
 
38 Collotype and Photo-Lithography. 
 
 somewhat readily take colour off the plate they must 
 be first rolled up in a thinner ink and a separate slab. 
 According to " Lithographia " these indiarubber 
 rollers may be cleaned with lye, or strong alcoholic 
 spirit. If cleaned with turpentine it may be 
 advantageously followed by rinsing with soap and 
 water; by so doing the application of French chalk is 
 unnecessary. These rollers are, by comparison with 
 others, nearly indestructible, and therefore cheap, 
 notwithstanding their high first cost. 
 
 Velvet Rollers have latterly come much into 
 use, and are very successfully used for inking-up 
 the transfers in photo-lithography. They may be 
 also used in photo-zylography and photo-ceramic 
 processes, and also for certain purposes in collotype. 
 A necessary precaution is that the seam of the velvet 
 should always be kept off the surface subjected to 
 the rolling, and this may be carried out if the roller 
 is, say, ioj centimetres in diameter, a length of 31-2 
 centimetres may then be rolled without using the 
 
 .. VELVET. 
 SERGE. 
 
 [ / '// /JW'-PL-.- -PEAR WOOD. 
 
 BOX WOOD. 
 
 Fig. 5- 
 
 seam. The sketch will explain the construction. 
 The cylinder or stock is of pear-wood, and the 
 handles of box; first covering serge, which before 
 sewing on should be well shrunk in hot water ; over 
 this comes the velvet, the edges of which must not 
 overlap, but must be drawn together as close as 
 
Collotype and Photo -Lithography. 39 
 
 possible by means of thread. One advantage of this 
 roller is that it is ready for immediate use ; it must, 
 after use, be carefully cleaned before being placed 
 aside ; this is best done by repeated rollings on a clean 
 slab, and the judicious application of a little turpen- 
 tine. Turpentine only may be used to thin ink for 
 use with this roller. 
 
 Drying Rollers. In addition to those already 
 enumerated, all of which are intended for the appli- 
 cation of the ink to the plate, other rollers are 
 required, similar in construction, but covered with 
 wash-leather or cloth, and ased for the purpose of 
 absorbing superfluous moisture. For these it is 
 necessary, or at least advisable, that the frames be 
 so constructed that the rollers may be readily 
 removed when by continued use they have become 
 too damp. This method of drying the plates is far 
 preferable to the customary one of wiping with a 
 cloth, for even with the greatest care, if the printing 
 should extend over hundreds of copies, the layer 
 upon the plate will inevitably get scratched when 
 wiping or rubbing is resorted to, especially if isin- 
 glass which tends to soften the film be present. 
 
 Palette Knife or Spatula. It is unnecessary 
 to describe ; they are used for mixing the ink and 
 applying it to the slab and rollers, and for cleaning 
 the latter. They may be either of hard wood or 
 metal. 
 
 The Ink Slab may be either of slate, a litho- 
 graphic stone, or a sheet of strong zinc securely 
 attached to a block of wood truly planed. 
 
40 Collotype and Photo-Lithography. 
 
 The Press is an indispensable requisite for 
 printing operations. There are small wooden hand- 
 presses, especially constructed for collotype, which 
 may be purchased at a very low price .4 to 5 ; 
 but the more economical way is to procure a 
 small lithographic press constructed of iron. This 
 will not only be found more durable, but it may, 
 if occasion arise, be used either for lithographic 
 or zincographic printing, as it will bear the necessary 
 pressure, which is greatly in excess of that applied in 
 collotype printing. The hand-press constructed by 
 Sutter is a form that may be strongly recommended. 
 If the output of prints is to be large, a steam machine 
 will be necessary, the cost of which will be not less 
 than 200 to 250. Fig. 6 represents a press which 
 has been largely used for collotype. D is the bed or 
 carriage upon which the plate is fixed in the manner 
 described further on. By turning the crank handle 
 C the bed is carried under the scraper, which is 
 secured in the scraper-box A. The scraper is kept 
 in position by the lever B. The scraper-box is repre- 
 sented as closed down in the illustration, but in 
 actual practice it would not be in the position shown 
 until the tympan-frame E had been lowered. 
 
 The Tympan, of either leather or thin sheet 
 zinc or brass, is marked F in the illustration. All iron 
 portions of the press subject to friction should be 
 frequently cleaned and carefully oiled with a good 
 machine-oil. 
 
 The Scrapers should be of either pear tree, 
 
Collotype and Photo-Lithography . 
 
 lime, maple, or preferably box, with a blunt bottom 
 edge, which should be planed true, and finally 
 finished by rubbing on a sheet of glass-paper placed 
 upon a perfectly flat surface. They must be 
 adjusted with even more precision than is neces- 
 sary in lithography, as owing to the difference 
 in the printing surface, the same pressure cannot 
 with safety be applied. With plates or stones 
 of large size it will be found that the pressure 
 of the scraper will be unequal, greater pressure beino- 
 
42 Collotype and Photo-Lithography. 
 
 exerted in the centre than upon the edges of the 
 printing surface. Many printers, to counteract this 
 tendency, slightly scrape away or hollow out by 
 means of a piece of glass the centre of the scraper. 
 With sufficient pressure and plenty of elastic packing 
 between the printing paper and the tympan, this 
 slight difference may be easily overcome. Several 
 scrapers should be provided of various lengths, so that 
 one of suitable size may be always available to suit the 
 particular work in hand. It should always be slightly 
 longer than the width of the picture, but shorter than 
 the width of the stone or plate. By pressing the 
 edge of the scraper to the surface of the latter and 
 looking towards a window no light should be visible 
 between the two surfaces. If the edges of the 
 scraper are carefully rounded, it may be covered with 
 a strip of wash-leather,* smooth side outwards, and 
 secured by means of tacks, by which arrangement 
 the pull will be easier, the impression more even, 
 and the tympan and scraper will last longer. The 
 accompanying sketch represents one of Poirier's 
 special collotype presses, constructed entirely of 
 iron. The details are so clearly shown in the 
 engraving that after the description already given it 
 will be unnecessary to point out further details. 
 
 White Margins to Pictures. To facilitate 
 the production of pictures with white margins, instead 
 of using a mask of paper either oiled or treated with 
 a varnish, an arrangement has been introduced, as 
 represented in fig. 7, the design of which is due to 
 
 * This is necessary only with metal tympans. 
 
Collotype and Photo-Lithography. 
 
 43 
 
44 Collotype and Photo-Lithography. 
 
 Mr. Raph. Schlegel. The drawing is not perspec- 
 lively correct, but is made to show as clearly as 
 possible the arrangement and manner of working. 
 The scraper not shown in the illustration works 
 on the tympan O. A, carriage or bed of the press, 
 carrying the printing plate. B, a slide of light wood. 
 This prevents the frame D and the printing paper M 
 coming in contact with the plate before the impres- 
 sion is actually being taken by the scraper. The 
 wooden slide bridges over the plate, and may be 
 15 to 25 millimetres higher than the plate itself. 
 When the rolling up or inking of the plate has taken 
 place the slide is pushed so far forwards as to 
 allow only just sufficient room for the scraper to rest 
 upon the plate. The action of the scraper during 
 the taking of the impression causes the slide to work 
 out, and allows the paper to come in contact with 
 the print layer. E E are adjustable buttons to 
 regulate the traverse of the carriage when printing. 
 D is a second frame necessary to carry the strips of 
 thin zinc, Ef Ef, Eg Eg, which entirely protect the 
 edges of the paper to be printed upon, and so pro- 
 duce an impression with a white margin. These 
 strips may be almost instantly adjusted to give any 
 required size. The frame D must be so much 
 smaller than the frame L as to be easily covered 
 by the latter, allowing for the projecting screws 
 and nuts of the clamps f. The zinc strips should 
 be reduced to a feather edge on the sides next 
 the picture, and should have secured to them 
 strips of fine paper (foreign letter-paper), which 
 
Collotype and Photo-Lithography. 45 
 
 should extend over the edges about three millimetres, 
 to prevent damage to the gelatine layer, f f are 
 clamps for the zinc strips Ef. They are put through 
 the slots, and the tension adjusted by the nuts. 
 The zinc strips are perforated by two holes at each 
 end, and secured to the clamps by means of screws. 
 Eg are also zinc strips ; g clamps provided with 
 two holes, in each of which a hook is inserted. 
 Corresponding with these a second pair of hooks are 
 inserted in holes in the frame I, the hooks being 
 connected together by the strong indiarubber bands 
 h. This gives to the strips Eg a certain amount of 
 elastic tension. The clamps K are also adjustable 
 in slots, and similar to f ; L, frame for the reception 
 of the tympan ; M, large clamp for stretching the 
 elastic sheet O ; N, zinc tympan, greased to 
 facilitate its movement under the scraper, it also 
 prevents grease penetrating the sheet O ; P, a 
 bracket on bed A, against which the tympan frame 
 rests when raised and thrown back. The arrange- 
 ment is used as follows : When the plate has been 
 satisfactorily inked or rolled in, the slide or bridge 
 B is adjusted over the plate, leaving a strip of about 
 three mm. uncovered to allow of adjustment of the 
 scraper. Lower the frame D in which the zinc 
 strips have been adjusted to the size of picture ; the 
 printing paper is placed over this slide, and covered 
 with a few sheets of paper backing. The tympan 
 frame L, together with the sheeting and greased 
 zinc plate, are lowered upon the work, the scraper 
 adjusted, and an impression taken. 
 
46 Collotype and Photo-Lithography. 
 
 CHAPTER V. 
 
 CHEMICALS AND MATERIALS FOR COLLOTYPE. 
 
 ELATINE. The basis of the Collotype pro- 
 cess is gelatine the finest purified animal glue 
 and the important part it plays in the process 
 demands an acquaintance with its properties, which 
 are found to differ widely, according to its origin and 
 method of preparation. Gelatine suitable for Collo- 
 type should be free from all impurities particularly 
 alum, which is not infrequently added in small 
 quantities during manufacture. Dr. Eder, in par- 
 ticular, has made most minute examinations of 
 various samples, more especially with regard to their 
 suitability for Collotype, Carbon, and the Galvano- 
 graphic processes, and his opinion, agreeing with 
 that of other experimentalists, is here quoted : 
 
 The two principal modifications of gelatine are 
 those produced from bones, sinews and skins of 
 animals, and from the air bladder of the sturgeon, the 
 latter variety, better known underthe name of isinglass,. 
 represents, from a chemical point of view, glue in the 
 purest form. On account of its high price and ever- 
 varying quality as found in commerce, it must in 
 practice give place to aglueor size containingchondrin, 
 and prepared from bone and gristle. Another ob- 
 
Collotype and Photo-Lithography. 47 
 
 jection is, that plates prepared with an admixture of 
 isinglass are less durable than those containing 
 gelatine only. On the other hand, it certainly 
 possesses advantages of its own, which will be more 
 fully considered hereafter. A gelatine suitable for 
 collotype must absorb plenty of water and swell out, 
 but not liquefy after having been soaked in cold water 
 for twenty-four hours. Gelatine or isinglass prepared 
 from the bladder will not stand this test, but, on the 
 contrary, partially disintegrate. The consistency 
 and bearing capacity of a jelly formed by dissolving 
 gelatine in water by means of heat and allowing it to 
 cool, form, in the opinion of Lipowitz, a safe and 
 reliable means of forming a judgment as to its suita- 
 bility for collotype. Dissolve by first soaking five 
 grammes in 45 cm. of distilled water for several hours, 
 afterwards apply heat, and allow to stand twelve 
 hours to set. For purposes of comparison this should 
 always be done in a glass of the same diameter. A 
 small tin or zinc slip is placed across the top of the 
 glass vessel containing the jelly ; through the centre 
 of the tin a hole is pierced, through which a wire 
 moves easily up and down. To its bottom end is 
 soldered a piece of tin, of about 15 cm. diameter, the 
 convex side lying upon the surface of the gelatine. 
 On the other or upper end a small funnel is placed, 
 large enough to contain ij kilo, of small shot. The 
 weight of the wire and funnel being ascertained, it 
 will be a simple matter, by also weighing the shot, to 
 calculate the weight required to sink the instrument 
 
48 Collotype and Photo-Lithography. 
 
 into the jelly, and to ascertain with accuracy its 
 weight-bearing capacity and proof of the relative 
 value of various samples for Collotype printing. If 
 otherwise suitable, the variety capable of supporting 
 the greatest weight before yielding will be the one to 
 select. The power of absorption of different sam- 
 ples varies considerably ; for example, the Collotype 
 gelatine of Creutz absorbs in two hours 30 parts of 
 cold water poured over it. Nelson's patent opaque, 
 in the meantime, only absorbs five parts, but after a 
 further period of 4^ hours the difference is equalised, 
 as it will absorb 25 parts more of water, making 
 altogether exactly 30 parts. This experiment proves 
 the latter to be a harder quality than that of Creutz, 
 and it necessarily requires a somewhat different 
 treatment for the production of the best results. 
 
 Isinglass or fish glue, although, as before stated, 
 a finer quality of glutin than the ordinary gelatine of 
 commerce, is, on account of its high price and vary- 
 ing quality, comparatively little used. The addition 
 of this substance also softens the gelatine layer. On 
 the other hand, it possesses certain properties which 
 render its use at times desirable ; for instance, it 
 does not dry so completely as gelatine, the layer 
 prepared with it consequently gives cleaner and 
 more even proofs, a point particularly noticeable 
 in the earlier impressions. Such prints will also 
 exhibit greater brilliancy, and this is of especial con- 
 sequence in work produced from photographs from 
 nature, in which class of work the half-tones are too 
 
Collotype and Photo-Lithography. 49 
 
 often wanting. Some operators take even equal 
 parts of isinglass and gelatine, but such layers must 
 be very thin, and dried quickly. Thick layers are 
 liable to crack or fly, and in use to refuse to take the 
 ink, which must for such film be used in greater 
 quantity and thinner than when gelatine alone is 
 employed. A solution of isinglass is not so readily 
 prepared as one of gelatine. It is necessary to allow 
 it to soak in cold water for from twelve to twenty 
 hours, and the temperature then gradually raised to 
 nearly boiling point, at which heat it should be 
 maintained for some time longer, and then filtered 
 through flannel into the gelatine solution. In print- 
 ing from these plates, particularly when the propor- 
 tion of isinglass exceeds one-third the amount of 
 gelatine, there is a disagreeable tendency of the 
 printing paper to adhere in the high lights that is, 
 in those parts of the print layer which are repre- 
 sented in the negative by entire opacity as in the 
 sky of a landscape or a background which has been 
 "stopped out" on the negative. On other portions 
 of the plate where the light has more fully acted 
 during the printing in the printing frame this 
 troublesome defect will not be observed. The fault 
 is more noticeable when the dull enamel paper is 
 used, while a hard, well-sized letter paper presents 
 the other extreme. Further details of printing 
 papers will be found in another chapter. 
 
 In the introductory chapter of this work the 
 photo-chemical qualifications of the bichromates of 
 
50 Collotype and Photo -Lithography. 
 
 ammonium and potassium with regard to collotype 
 are considered. 
 
 Bichromate of Potassium is found in the 
 well-known rich orange-red crystals. It is readily 
 soluble in cold water (i.io). It may be easily 
 recrystallised and purified readily out of either a 
 hot, warm, or cold solution, and forms in thin 
 layers of fine crystals. Therefore, in using it for 
 collotype, care is needed not to exceed the strictly 
 necessary proportion, as the plate may be hope- 
 lessly spoiled by the partial crystallisation of the 
 salt, which will probably show during the process 
 of drying. The maximum addition of bichro- 
 mate of potassium in proportion to the weight 
 of the gelatine may differ according to the pecu- 
 liarities of the latter. Dr. Eder considers about 
 A to T 4 <j by weight of this salt in a dry state may be 
 added to a gelatine, which will absorb from six to ten 
 times its weight of water, without fear of crystallisa- 
 tion. There are, however, many gelatines that are 
 incapable of working with more than T 2 ^. Rapid 
 drying of the plate in a current of air, and at a 
 temperature of 40 C., will, to some extent, obviate 
 this objectionable feature. By reason of its com- 
 parative insensitiveness to light and this facility of 
 crystallisation, and notwithstanding its comparative 
 low price, it is now far less used in collotype than 
 
 Bichromate of ammonium, the crystals of 
 which somewhat resemble those of the potassium salt. 
 In colour they are of a browner hue, and readily 
 
Collotype and Photo-Lithography . 51 
 
 distinguishable, since when heated on platinum 
 deflagrates, emitting sparks and leaving a residuum 
 of very finely-divided oxide of chromium. The 
 ammonium salt does not, however, so readily 
 crystallise on account of its considerably greater 
 solubility in water compared with bichromate of 
 potassium. By comparison, 12 parts of the ammo- 
 nium salt are equal to 15 parts of that of potassium. 
 At least J to J more of the former may be used 
 without disadvantage or fear of it crystallising out ; 
 it will, on the contrary, improve the quality of the 
 film or layer. The ammonium salt will also be 
 found comparatively more soluble in hot water, but 
 care must be exercised that the solution never 
 reaches the boiling point, neither should the heat of 
 the drying box ever exceed 50 to 60 C., or the 
 films will present a pale brown appearance, and will 
 prove alike insensitive and partially insoluble. The 
 single and tri-salts, offering no advantages over those 
 already described, may be dismissed without further 
 consideration. It may be remarked for non-chemists 
 that the addition of any acid to the chromated 
 gelatine solutions inclines to the formation of tri- 
 chromates of the alkalis ; and, on the contrary, the 
 addition of free ammonia, or any other free alkali, 
 produces simple chromates. The addition of am- 
 monia to the chromated solution has been strongly 
 advocated in many quarters, but as the result of 
 numerous experiments, it may be definitely stated 
 that the supposed advantages are more than counter- 
 
52 Collotype and Photo-Lithography. 
 
 balanced by the numerous disadvantages arising from 
 such addition. The mixing, in equal or other pro- 
 portions, of the potassium and ammonium salts has 
 been recommended, but there is no real gain or 
 sufficient reason for preferring any of these combina- 
 tions to the ammonium salt alone. Besides the 
 chromates of the alkalis, several other salts as well 
 as acids are used in Collotype printing, although 
 seldom, and then only in small quantities and 
 for special purposes, such, for instance, as 
 hardening the print layer, or for the purpose of 
 facilitating the retention of moisture in the film. 
 For the former purpose small quantities of chrome 
 alum are sometimes added ; while for the latter 
 chloride of sodium or chloride of calcium are some- 
 times added to the chromated gelatine solution at 
 the time of coating the plates, or are added as 
 ingredients to the so-called etching or damping 
 solution which is frequently applied to the plates 
 during the printing. Glycerine answers for this 
 purpose, and is to be preferred. It should be borne 
 in mind that all additions to the film to facilitate its 
 retendon of moisture lessen its adhesiveness to its 
 support. And with regard to the direct addition of 
 the substances mentioned to the film during the 
 preparation of the plates, it is not very apparent how 
 such readily-soluble matters can remain in the film 
 after the prolonged and careful washing the plates 
 should be subjected to after exposure in the printing 
 frame. On these grounds the addition of such sub- 
 
Collotype and Photo-Lithography. 53 
 
 stances to the damping solution is more rational and 
 certainly more effective. 
 
 Alum and Chrome-Alum causes the gelatine 
 to set sooner without precipitation, and harden the 
 layer considerably after drying, and although gela- 
 tine, as well as glue, always contains more or less 
 chondrin, which is precipitated by alum, great care 
 is necessary in the addition of the latter ; and it is 
 better that such addition should be made imme- 
 diately before the hot solution be poured upon the 
 plates, otherwise a precipitation will ensue, which, 
 although very finely divided and at first scarcely 
 visible, will become more apparent during the 
 drying of the plates, and finally show in the picture 
 in innumerable white spots. 
 
 Silicate of Soda is almost indispensable as a 
 substratum in the preparation of collotype plates, 
 although many practical workers still adhere to the 
 method originally proposed and practised by J. 
 Albert, of Munich, who used as a substratum a 
 chromated solution of galatine and albumen, ren- 
 dered either partially or wholly insoluble by exposure 
 to light. The silicate is here considered as having 
 about the consistency of syrup. If more fluid the 
 adhesive power of the substratum will not realise 
 expectations, and the plates will require very careful 
 handling if even a few hundred impressions are 
 required. 
 
 The composition of the film, the exposure of 
 the plate through the back, and the careful treat- 
 
54 Collotype and Photo-Lithography. 
 
 ment of the layer in the actual printing operations 
 are all matters which considerably affect the "life" 
 of the plate, and to which we shall again return. 
 
 Chloride of Zinc is used for hardening special 
 parts of the collotype plate, and is easily prepared 
 by dissolving to saturation sheet zinc in hydro- 
 chloric acid, filtering, and reducing as circumstances 
 may demand. 
 
 Tannin and Tannic Acid in strong solution 
 harden the film, and may be applied to certain parts 
 to cause it to "take" the ink. For instance, to 
 remove, or rather harden, spots which refuse the ink 
 and consequently show upon a dark ground ; and 
 also to write names or titles to the plates. Written 
 additions of this character must, of course, be 
 reversed, as in lithography. The addition of tannin 
 to the chromated gelatine before coating the plate 
 is recommended by Waterhouse, he considering uch 
 addition confers greater lasting power to the films 
 so treated. 
 
 Cyanide of Potassium and Ammonia. All 
 alkalis or carbonates of the alkalis have a directly 
 opposite effect upon the printed layer to that last 
 referred to. By the judicious use of one or the other 
 of these agents spots printing light or dark may be 
 either removed or considerably modified. 
 
 Glycerine and Sugar and similar easily 
 soluble organic substances, added to the chromated 
 gelatine, would assist the easier and evener damping 
 of the plate, but render it more susceptible to 
 
Collotype and Photo -Lithography. 55 
 
 damage, and the desired effect is better attained by 
 suitable additions to the damping water. 
 
 Organic Acids. Citric acid and tartarfe; acid 
 are recommended as additions to the chromated gela- 
 tine, partially as influencing the so-called "grain 
 and also as additions to the damping solution to 
 facilitate the production of cleaner prints. Experi- 
 ence with these substances shows that the print layer 
 suffers from their use, and for clearing up a plate 
 inclined to yield dirty impressions a weak solution of 
 ammonia is far preferable. 
 
 Nitric Acid has even been recommended for 
 occasionally damping the plate in certain cases, after 
 which the most delicate half-tones f should be repro- 
 ducible. An experienced collotypist ought never to 
 be under the necessity of adopting such desperate 
 remedies, which more often than not rapidly and 
 entirely spoil the plate, and it is better to at once 
 prepare a new one. 
 
 Ox Gall remains to be mentioned as exercising 
 a beneficial influence upon the print layer under 
 certain circumstances. It considerably hardens the 
 gelatine, and tends to reduce the annoying tendency 
 of the film to adhere to the paper in the high lights. 
 Ox gall was first used at the Royal Printing Works 
 in the "glass " printing process there utilised for the 
 reproduction of line subjects. Some operators of 
 eminence consider that in collotype its use should be 
 strictly confined to lineal representations, as by its 
 continued use the half-tones are partially lost. 
 
56 Collotype and Photo-Lithography. 
 
 INK AND PAPER. 
 
 Of great importance is the careful selection of 
 the materials for the printing proper i.e., the 
 printing inks and papers, and the sometimes neces- 
 sary admixtures of the former. 
 
 Printing Ink. The most simple and suitable 
 of all greasy or oily printing ink is the best chalk ink, 
 as used in lithography. It is composed of finest lamp 
 black thoroughly incorporated with boiled linseed oil 
 (varnish). The collotypist must, in addition to 
 different coloured ink for mixing with the black, be 
 provided with thin boiled oil (middle varnish), and 
 also turpentine and olive oil, the latter being used to 
 thin or reduce the printing inks, which, as usually 
 supplied to the trade, are too stiff for immediate use. 
 When in printing it is necessary or intended to use 
 an admixture of several colours, they must be first 
 well ground in turpentine and the latter allowed to 
 evaporate, A small addition to the chalk ink of 
 indigo or Prussian blue greatly improves its colour 
 and printing power, but may be considered more 
 suitable for the reproduction of line or stipple sub- 
 jects. A dash of Venetian red or carmine imparts 
 to the chalk ink a warmer tone, resembling the colour 
 of an ordinary silver print. Whoever ventures on 
 colour printing must be able to prepare all the 
 necessary combinations with the greatest exactness, 
 and should use for each a special inking slab and 
 roller. In the chapter dealing with the printing, 
 further particulars will be given as to the mixing 
 and thinning of the colours. J 
 
Collotype and Photo -Lithography. 57 
 
 The Quality of Paper suitable for collotype 
 may be next considered. Without doubt the best 
 is that known as dull enamel, or chalk paper, which 
 is now supplied of a pink tone as well as of the 
 ordinary white quality. It should not be glossy or 
 adhere too strongly to the printing surface, as the 
 enamel will, under such circumstances, be partially 
 or wholly torn from the paper, a difficulty equally 
 observable whether the paper be used damp or dry. 
 As previously observed, the adhesive power of the 
 printing surface increases with the softness of the 
 same. This may arise from using a small percentage 
 of bichromate or a short exposure to light, in which 
 cases it is always more apparent in such parts, as 
 the densest portion of the negative may have been 
 entirely protected during the copying in the printing 
 frame, or it may arise from the addition of too great 
 a proportion of isinglass. On the other hand, a gela- 
 tine film strongly chromated, proportionately longer 
 exposed, and in which there is no isinglass, will be 
 less likely to exhibit this annoying tendency. 
 
 Well-sized fine glazed papers generally adhere 
 least, and are usually laid on dry. When the im- 
 pressions are to be issued without glaze very thin 
 fine -surfaced cardboard not enamelled is fre- 
 quently used, and the margin of the printing plate 
 covered with a suitable mask. Any well-sized paper 
 possessing a fine surface may be used. Impressions 
 
58 Collotype and Photo- Lithography. 
 
 on such paper may be passed through a weak solu- 
 tion of gelatine, and after drying, rolled, varnished, 
 mounted and again rolled. Any retouching must be 
 done immediately after the sizing, and before the 
 application of the varnish. Enamelled papers require 
 a special glaze, not a lacquer, or are finished without 
 glaze at all. 
 
Collotype and Photo-Lithography. 59 
 
 CHAPTER VI. 
 
 PREPARATION OF THE COLLOTYPE PLATE. 
 
 THE well-polished glass plate must be thoroughly 
 cleaned with alcohol and ammonia, and it 
 should be ascertained that the surface is entirely free 
 from scratches. It is then coated with the substratum, 
 consisting of a dilute solution of silicate of soda and 
 albumen. The following formula is in constant use 
 by many practical workers of experience, and answers 
 every requirement : 
 
 Distilled water 8 parts. 
 
 White of egg whisked ... ... .. 7 
 
 Silicate of soda (of the consistency of syrup) 3 ,, 
 
 This mixture should be well beaten to a froth or put 
 in a bottle with pieces of broken glass, well shaken, 
 .and placed aside to settle for half-a-day. Then filter 
 through paper, which should be replaced so soon as 
 the pores become choked. To facilitate the operation 
 the filter paper should before use be moistened with 
 distilled water. The surface of the plate should be 
 flooded with water, and coated as evenly as possible 
 with the above solution, a small glass rod being made 
 use of to assist the flow. Air bubbles must be re- 
 moved, and by quickly tilting the plate the super- 
 fluous solution run off; this should not be used to 
 
6o Collotype and Photo-Lithography. 
 
 coat other plates without being again carefully fil- 
 tered. If the substratum be thin, it is not necessary 
 to wash the plate after drying, but after standing 
 aside two days to harden, with dusting and warming, 
 they may be coated with the chromated solution of 
 gelatine. If small crystal formations appear on the 
 surface the plate should be well washed and again 
 dried before proceeding further. The following 
 formula for substratum is due to M. Thiel, senior ; 
 it contains less silicate, and the washing before 
 applying the sensitive coating is never necessary : 
 Distilled water .. ... ... ... 36 parts. 
 
 White of egg ... ... ... ... 20 ,, 
 
 Silicate of soda ... ... ... ...6-2 ,, 
 
 Stale Beer. Albumen is sometimes replaced 
 by beer, from which by frequent outpourings the 
 carbonic acid has been removed, and to which 
 caustic potash has been added until it fails to show 
 an acid reaction when tested with blue litmus paper 
 (about three to five grammes of caustic potash to 
 the litre of beer will be necessary). To a litre of 
 beer so prepared is added J kilo, of silicate of soda. 
 The main points in this and also the following opera- 
 tions are careful filtration, even coating and drying 
 in a clean place entirely free from dust. Plates 
 previously used or somewhat scratched must before 
 further use be thoroughly cleaned and the face 
 reground with the finest emery powder. 
 
 The Sensitising Solution. This is manifestly 
 the most important matter in the Collotype process, 
 for on it depends not only the durability of the 
 
Collotype and Photo-Lithography. 61 
 
 printing plate, but also the method of procedure in 
 the subsequent operations. It may be here intimated 
 that plates prepared by the very best formula cannot 
 be expected to yield good impressions if the whole of 
 the manipulations are not carried out with the 
 greatest care, and it should be noted 
 
 1. That neither too much nor too little of the 
 chromated gelatine should be allowed to remain upon 
 the plate. It is impossible to lay down a hard and 
 fast rule, and the exact amount must be determined 
 by the experience of the operator. Of equal 
 importance, and naturally connected with this 
 operation, is 
 
 2. The even distribution of the solution, the 
 flow of which may be assisted or directed by the aid 
 of a small glass rod, and by allowing it to run off more 
 or less at each of the four corners of the plate. 
 Considerable experience has demonstrated that the 
 coating is applied most easily and in the evenest 
 manner by resting the plate previously warmed to 
 about 45 C. as horizontally as possible on the cork 
 of a heavy bottle, the latter standing in the centre of 
 an earthenware dish. A sufficient quantity of the 
 solution, carefully filtered, and heated to 45 to 50 
 C., is then poured on to the centre of the plate and 
 rapidly spread over it with a glass rod, previously 
 well warmed. So soon as the surface of the plate 
 has been entirely covered a further supply of the hot 
 gelatine solution is quickly poured on and partially 
 run off at each corner. A scarcely perceptible inch- 
 
62 Collotype and Photo-Lithography . 
 
 nation should be given to the plate, otherwise the 
 layer will be too thin ; it ought to be about the 
 thickness of four or five sheets of Rive paper of 
 8 kilo, per ream. It should be borne in mind that 
 the addition of isinglass will necessitate a com- 
 paratively thinner layer than when gelatine is used 
 alone. 
 
 To obviate the gelatine coating becoming un- 
 even great care must be exercised in removing the 
 plates when coated to the drying-box, the levelling 
 screws of which have been adjusted with great 
 accuracy. The box should be heated to a tempera- 
 ture not exceeding 50 C. 
 
 To satisfy the adherents of isinglass, two 
 eminently satisfactory formulae are here given 
 
 WITH GELATINE ONLY. 
 
 Collotype gelatine 6 grams. 
 
 Water ... 70 ccm. 
 
 The gelatine is first soaked in the water for one 
 hour, and then complete solution effected at a 
 moderate temperature, and the solution filtered 
 through best filter paper. Boiling heat is never 
 required. Japanese filter paper is the very best. 
 Heat will be necessary during the operation, which 
 may be conducted either in the drying box or a warm 
 oven. When filtered, add, with constant stirring, 
 8 ccm. of a solution of bichromate of ammonium in 
 water (i in 8, so that 8 ccm. solution contains i 
 gramme of the ammonium salt), which should also 
 be thoroughly filtered before addition to the gelatine. 
 
Collotype and Photo-Lithography. 63 
 
 The combined solutions being well incorporated, 
 clear and free from air bubbles, should, as previously 
 described, be heated to 40 or 50 C., poured upon the 
 warmed plate, and at once conveyed to the drying 
 box, the temperature of which has been slightly 
 raised. The box should be closed, and gradually 
 increased to 50 C., at which heat it should be steadily 
 maintained until the drying is complete, which usually 
 occupies one to one and a-half hours, varying some- 
 what according to the thickness of the coating and 
 the strength of air current, which is necessary to the 
 proper and rapid drying of the films. It may, under 
 some circumstances, be necessary to augment the 
 admission of air ; this may be done by slightly raising 
 the lid of the drying box. The current must freely 
 circulate in all parts of the box, and remain as con- 
 stant as possible. If subjected to sudden fluctuations 
 in the air current or temperature, the plates will dry 
 unevenly, and endless troubles ensue. 
 
 The Grain. The so-called grain which is 
 necessary for the printing first shows itself on the 
 completion of the washing of the plates after print- 
 ing in the copying frame. It is a peculiar, net-like 
 formation, varying in fineness, and similar in 
 character to the unwelcome appearance known to 
 carbon printers as reticulation. It arises in conse- 
 quence of the uneven distribution of the soluble 
 layer in comparison to the substratum. In Collotype, 
 its production is promoted by thicker layers and 
 slower drying at a temperature of 45 to 50 C. The 
 
64 Collotype and Photo-Lithography. 
 
 addition of isinglass also seems to aid the production 
 of grain. Certain varieties of gelatine which possess 
 great power of absorption give a smaller grain. 
 Creutz's gelatine may be mentioned as an example 
 of this class. An addition in small quantities of 
 dilute acid, particularly those of organic origin, as 
 acetic or tartaric, tend likewise to the production of 
 grain. Insoluble powders, as of glass or flint stone, 
 may be added, but only in the very finest state of 
 division, and in very small quantities. 
 
 FORMULA WITH ISINGLASS. 
 
 Two grammes of the best Russian isinglass are 
 cut up into the smallest possible pieces with a pair 
 of sharp scissors, soaked in 25 cc. of water for 12 
 hours, heated nearly to boiling point until solution 
 is effected, and then filtered while hot through close 
 flannel. Cover six grammes of good Collotype gela- 
 tine with 50 ccm. of water and allow to stand, heat 
 nearly to boiling point and thoroughly incorporate 
 the two solutions, again, while hot, filter through 
 paper or close flannel. To this is added n cc. of 
 the filtered solution (1*8) of bichromate of ammonium, 
 as previously referred to. The complete solution is 
 then heated to 50 C., or should it exceed that tem- 
 perature it is allowed to cool to it, and the plates 
 warmed, coated, and dried in the manner previously 
 described. It is not advisable to overcrowd the 
 drying-box by attempting to dry too many plates at 
 the same time : it necessitates a too frequent ex- 
 amination of the contents and so interferes with the 
 
Collotype and Photo-Lithography. 65 
 
 evenness of the drying, and as this is a point of even 
 vital importance no risk should be incurred. 
 
 The plates being properly dried allow them to 
 remain in the box for some time longer, the source of 
 heat being either removed or extinguished, and the 
 whole allowed to cool gradually. If the plates are 
 removed too quickly in their fully-heated condition- 
 particularly when thickly coated the too rapid con- 
 traction of the glass will crack and destroy the film ; 
 by gradual cooling such accidents are avoided. 
 When finished the plates may be kept in a cool, dry 
 place for two or three days. Many operators keep 
 them this length of time purposely, believing they 
 thereby obtain finer results. The plates so kept 
 must, of course, be thoroughly shielded from actinic 
 light. 
 
 Negatives, with regard to their suitability for 
 Collotype, may here be considered, as the after result 
 naturally depends considerably on their adaptability 
 to the process. They should be quite free from fog 
 or yellow stain, and for half-tone subjects not too 
 intense. The greatest difficulties will present them- 
 selves in the production of portraits or such work 
 from nature by the Collotype process. Photographer 
 and printer ought, so to speak, to work hand-in-hand. 
 The negative must show the finest gradation from- 
 clear glass in the shadows to the necessary density 
 in the high lights, quite free from veil or fog, and 
 intensified very little, if at all. They should be 
 produced in a studio where the light is thoroughly 
 
66 Collotype and Photo -Lithography. 
 
 under control. If not to be stripped all negatives 
 should be taken on patent plate and protected by a 
 coat of varnish, sufficiently thin to offer no obstacle 
 to the production of sharp prints, and yet sufficient 
 to obviate in a great measure the risk of damage by 
 the pressure it is subjected to in the pressure frame 
 in contact with the unyielding surface of the Collo- 
 type plate. The risk of breakage at this stage 
 always renders stripped films preferable, their elasti- 
 city better enabling them to withstand the pressure. 
 The gelatine layer applied to the negative before 
 stripping must be as thin and even as possible, as 
 from thick or uneven films it is almost impossible to 
 produce a sharp print. If the negative is of a line 
 subject, and it is desirable to have clear whites that 
 the impressions may resemble as much as possible 
 the original, the lines in the negative must be clear, 
 but the remaining portions of great density. The 
 ink for such work should consist only of pure chalk 
 printing ink, which will be generally found to give 
 stronger contrasts than the usual mixed Collotype 
 inks. 
 
 Retouching Negatives and Plates. The 
 negatives must have all defects made good by the 
 retoucher, all blemishes being moderated as far as 
 possible. Retouching on the Collotype plate or 
 print should not be required ; but this is seldom so, 
 as during the printing the negatives frequently sus- 
 tain slight damages. Retouching the printing surface 
 is seldom very successful. The alteration easiest 
 
. Collotype and Photo-Lithography. 67 
 
 effected is the removal of small light spots which 
 refuse to take the ink, and such may be removed by 
 touching with a fine brush dipped in a strong 
 aqueous solution of tannin, this alteration being 
 made upon the finished plate after it has been 
 washed and dried. With this tannin solution 
 inscriptions may be inserted which have to appear 
 black in the print. Or a solution of gum arabic, to 
 which has been added a solution of bichromate of 
 potassium, may be used, and after such addition the 
 plate is once again exposed to light. Writing which 
 has received too much exposure, and which should 
 appear in the finished print black on a white or light 
 ground, often appears white. This defect arises from 
 the gelatine on which the light has had little or no 
 action swelling to such an extent that the letters are 
 buried or sunk into the plate too deep to be touched 
 by the roller when the plate is inked. It may be 
 rectified by further thinning the ink with varnish. 
 The removal of dark spots from the print layer can 
 never be completely effected. Ammonia, cyanide of 
 potassium, oxalic and other acids have from time to 
 time been recommended, but this treatment will 
 prove effective for only a few impressions. 
 
 Negatives should therefore be very carefully and 
 systematically retouched and carefully preserved 
 from damage during the printing. Another method 
 of applying writing, such as the names of firms, &c., 
 is to get them printed from small type on thin gela- 
 tine films and attach them to a clear or erased por- 
 
68 Collotype and Photo -Lithography. 
 
 tion of the negative during the printing in the 
 pressure frame. Writing so added will appear as 
 white letters on a black ground. It will often be 
 found practicable to attach the written or printed 
 matter to the original while photographing, and so 
 include it in the negative at one operation. 
 
 Printing under the Negative. The printing 
 of half-tone plates is best performed in diffused light ; 
 to hit the exact exposure is as important as it is 
 difficult, and depends not only on the actinic power 
 of the prevailing light, but also on the quality of the 
 negative and the sensitiveness of the layer. The 
 greater the amount of bichromate the latter contains, 
 the greater its sensitiveness, and consequently the 
 exposure is shorter than for one containing less of 
 the sensitising salt. A thinner layer must not be 
 printed so long as a thicker one, or dark prints, 
 lacking in contrast, will result. On the other hand, 
 a thicker layer may be submitted to a com- 
 paratively longer exposure without harm ; the exact 
 time must not be greatly exceeded or it will happen 
 that the blackest portions, written titles for instance, 
 will not take the ink. During printing, one may 
 with advantage shade such portions a little. The 
 examination of the back of the Collotype plate is the 
 safest method of judging the correct exposure during 
 the copying, but every precaution must be observed 
 during such examinations that neither the plate nor 
 negative be moved from their original position. Only 
 when the negative is very clear may the picture be 
 
Collotype and Photo-Lithography. 69 
 
 seen by reflected light as a positive ; it will in such 
 cases appear on a dark ground. It will be found 
 difficult, particularly for a beginner, when making 
 an examination in the copying frame, to distinguish 
 between the dark original picture and the pale brown 
 image of the Collotype plate, as they naturally com- 
 pletely cover each other. By the dark brown tone 
 of the uncovered margin of the print layer a certain 
 indication is afforded of the completion of the 
 copying. 
 
 An Actinometer may be used as an exposure 
 gauge, as in carbon printing, and as a slight indica- 
 tion of the necessary exposure. When using the 
 small cube* photometer with chloride of silver paper, 
 five to seven tints may be printed, but the different 
 modifying circumstances previously referred to must 
 all be duly considered. Under a clouded sky in 
 winter, using a dense negative, it may take a whole 
 day to complete the copying, while in clear direct 
 sunlight, perhaps, from the same negative, a quarter 
 of an hour would suffice. 
 
 Masking should be resorted to to form a margin 
 at least an inch wide round the four sides of the 
 negative, either by painting round the same with 
 Indian ink, or by attaching to the negative strips of 
 opaque paper, or, better still, thin tinfoil. 
 
 Sunning. When sufficiently exposed, i.e., when 
 the bro\vn picture with all its half-tones and details 
 is complete, the plate is removed from the copying 
 
 * The scale actinometer is one requiring less attention. TRANS. 
 
70 Collotype and Photo-Lithography. 
 
 frame and placed, face downwards, upon a piece of 
 black velvet, and exposed for a short time five to ten 
 minutes to a good but not direct sunlight, so that it 
 may pass through the glass plate and harden the 
 back of the print layer. A sheet of ground glass 
 may be placed over the plate to thoroughly diffuse 
 the light, and prevent any scratches or damages 
 to the back of the glass plate producing any detri- 
 mental effect upon the printing surface. 
 
 Washing the Plate is the next operation. 
 The plate is removed into the dark room and placed 
 in clean cold water, which should be often changed 
 every half-hour unless an automatic washing ap- 
 paratus* is used ; this is continued until the plate 
 no longer has a yellow appsarance, and the picture 
 is visible only as a slight brown image. 
 
 Hardening the Film is effected by soaking it 
 for a quarter of an hour in a one per cent, solution 
 of alum. The plate is again washed, and the surface 
 evenly dried with fine tissue paper, and placed aside 
 for at least two days that it may thoroughly dry. 
 
 An Alcohol Bath is used by many operators 
 to immerse the plate in for half an hour after drying 
 it with paper, perhaps with the intention of drying 
 the film quicker, or to strengthen the layer and assist 
 the formation of the grain, but there is no gain by 
 this procedure, and, as the bath is an expense, it 
 may be omitted. 
 
 * Jefferies's Patent " Perfect " Washer is a very suitable appliance, and may 
 be used for Collotype plates, negatives, or paper prints. TRANS. 
 
Collotype and Photo-Lithography. 
 
 The Damping Solution, or so-called etching 
 fluid, is of much greater importance, and it is neces- 
 sary that the plate be submitted to it before printing 
 be attempted. 
 
 Tinted Grounds often enhance the appearance 
 of prints, and may be imparted to them by the addi- 
 tion of an aqueous solution of red, yellow, or other 
 suitable colour, to the damping solution, which is 
 applied in the ordinary manner. The plate is super- 
 ficially dried, inked up, and printed from in the usual 
 way. 
 
72 Collotype and Photo-Lithography. 
 
 CHAPTER VII. 
 
 NEGATIVES SUITABLE FOR COLLOTYPE. 
 
 A COLLOTYPE plate maybe readily produced 
 from any negative, but the highest results are 
 naturally only obtained when the negative is prepared 
 with a view to its special use. First should be 
 considered the question May the negative, without 
 detriment to the finished print, be utilised without a 
 reversal ? In the not very frequent case of this im- 
 portant point being immaterial, it is simply necessary 
 to produce the negative on patent plate, and it is at 
 once available for printing from. As the negative 
 may easily sustain damage in any of the various 
 operations, it should be thinly and evenly varnished ; 
 this, while affording protection, does not mar the 
 sharpness of the resulting print to any appreciable 
 extent. 
 
 Reversed Negatives. In the majority of 
 cases, the resulting copy has to exactly correspond 
 with the original as regards the position left and 
 right, and in such cases the negatives will have to be 
 reversed. This is usually effected in one of four 
 different ways 
 
 I. Reversal of the image by reflection with a 
 prism or mirror, or reversing the plate. 
 
Collotybe and Photo-Lithography . 73 
 
 2. Stripping the negative from the glass. 
 
 3. By the dusting on or powder process. 
 
 4. By the use of negative films. 
 
 The second is that usually adopted. With regard to 
 the special features desirable in negatives for Collo- 
 type, one giving a good silver print will answer 
 equally well for Collotype they should incline rather 
 to softness than the other extreme. It has been re- 
 marked that they should be as free from veil or fog 
 as possible, and may be intensified or not according 
 to the judgment of the operator. 
 
 Portraits from Nature, with their fine half- 
 tone, and at the same time necessary contrast of 
 light and shade, are the most difficult to reproduce in 
 Collotype. The negatives should be perfect in grada- 
 tion, and such as are usually only obtainable from a 
 talented operator who has the lighting of his studio* 
 entirely under his control. 
 
 Black and White subjects, on the contrary,, 
 for their satisfactory reproduction, require a negative 
 of the utmost density, but perfectly clear in the 
 lines. Such are better produced by the collodion 
 process, as directed for photo-lithography. For sub- 
 jects in lines or dots entirely free from half-tone, 
 photo-lithography is more suitable for reproduction 
 than Collotype, where price is a consideration. 
 
 Reversal by Reflection, by means of a mirror 
 or prism, necessitates a special and rather expensive 
 apparatus, and the exposure being somewhat length- 
 ened, it is, although quite successful, more suitable 
 for lifeless objects. F 
 
74 Collotype and Photo-Lithography. 
 
 Stripping the Collodion Film is a safe and 
 cheap procedure for producing the necessary reversal, 
 and in the subsequent printing operations the danger 
 of breakage, when compared with glass, is reduced 
 to a minimum. The glass plate, free from defects, 
 must be well cleaned, and it is safer, and renders 
 the stripping more certain, if it be covered with a 
 fine film of pure beeswax. This is best applied by 
 rubbing over the surface a few drops of a solution of 
 beeswax in benzole and carefully polishing, at the 
 same time avoiding the entire removal of the wax. 
 The piece of linen used in the operation should be 
 rubbed upon a lump of wax previous to the polishing. 
 The plate must on no account be gelatinised or 
 albumenised, except round the edge only, as a pre- 
 caution against premature slipping.* Use a tough 
 collodion, and otherwise proceed as usual for the 
 wet process. After the negative is finally washed 
 and dried it should be varnished with a thin solution 
 of gum arabic, to which has been added a few drops 
 of a solution of chrome alum. After complete drying 
 the margin or edges of the plate are rubbed with a little 
 tallow. To prevent overflow the plate is accurately 
 levelled and flooded with a solution of 10 parts gela- 
 tine soaked in 60 parts of water and dissolved by heat, 
 to which is added 20 parts of alcohol and 6 parts of 
 
 * Instead of wax the plate may be dusted over with powdered French 
 chalk, all traces of which are removed before applying the collodion. After 
 Fuch treatment the film is scarcely likely to leave the plate before required. 
 But as a further precaution, if the edges of two plates be drawn across each 
 other a rough edge will be produced, to which the collodion coating will 
 adhere tenaciously. TRANS. 
 
Collotype and Photo-Lithography. 75 
 
 glycerine, using i dram of the solution to each four 
 square inches. A few drops of phenyl, carbolic or 
 salicylic acid may be added to the solution as a pre- 
 servative, and the whole before use well filtered, 
 while hot, through linen. The hotter the solution 
 during the pouring on the more evenly the coating 
 will run upon the glass, and it may be assisted in its 
 flow by careful tilting of the plate. The use of 
 paper strips is dangerous, and, notwithstanding the 
 gum, extremely liable to damage the negative. 
 
 Reversal of the Plate, either collodion or 
 gelatine, is another method of securing reversed 
 negatives, and consists simply in inserting the sensi- 
 tised plate in the dark slide with the uncoated side 
 towards the interior of the camera. A modification 
 of the dark slide may be necessary, and it will be 
 obvious that the ground glass focussing screen must 
 be reversed, or the focus corrected after the insertion 
 of the dark slide by shortening the camera a distance 
 .equal to the thickness of the sensitive plate. Dry 
 plates present great advantages in this method, but, 
 in development, density must be judged entirely by 
 transmitted light, as the image is formed in, not upon, 
 the film. As the rays of light pass through the 
 glass to the sensitive surface, it is necessary that the 
 uncoated surface be quite clean, and the glass itself 
 .should be perfectly free from bubbles, scratches, or 
 other marks. 
 
 The plate should remain in its levelled position 
 for about fifteen minutes to set and then be carefully 
 
76 Collotype and Photo-Lithography. 
 
 removed to a safe and airy position >. gelatine side 
 outwards, and allowed to dry. This operation will 
 probably take two days ; the hot gelatine layer 
 should be about 3 mm. thick. The negative may 
 then be coated with a toughened collodion (one or 
 two per cent, of castor oil added to plain collodion). 
 The plate is placed aside, and in an hour will 
 probably be dry and ready for the next and final 
 operation. Cut with a knife through the film, take 
 it by one corner, and, without pause or hesitation, 
 strip it from the glass. 
 
 Any necessary retouching should be done upon 
 the gelatine surface after roughing it sufficiently with 
 pumice powder to enable it to take the pencil, and 
 all such work must be completed before removing 
 the film, particularly if it has been damaged, as in 
 such places the colour used in retouching would 
 cause an adherence, and the film would almost 
 assuredly tear in stripping. 
 
 Upon the quantity of gelatine solution used the 
 nature of the film depends. It should be entirely 
 free from air bubbles. Too thick a layer almost 
 always cockles, and does not lie flat during printing, 
 in consequence of which portions of the picture will 
 not be sharp in the print. On the other hand, too 
 thin a layer is extremely awkward to handle in the 
 larger sizes, and it is preferable to transfer it in a 
 reversed position to a sheet of plate glass coated 
 with indiarubber solution. 
 
 Gelatine Plates for Stripping are in the mar- 
 
Collotype and Photo-Lithography. 77 
 
 ket. In their preparation it is necessary to first coat 
 the glass with a solution of yellow wax in benzole, or 
 an indiarubber solution, before coating with emul- 
 sion, such plates being known as strippers in America 
 .and Germany. When finished, the negative is 
 placed, together with a gelatine film or " skin" in 
 a solution of glycerine and water, both are with- 
 drawn together, a squeegee applied to remove the 
 superfluous solution, and the negative, with its ad- 
 hering skin, placed aside to dry. Afterwards the 
 edges of the film are cut through, and the negative 
 removed from the glass. 
 
 STRIPPING THE FILM OFF GELATINE NEGATIVES 
 FOR COLLOTYPE. 
 
 In the Photographisches Archiv, Mr. Wilh. Otto, 
 a well-known German Collotype printer, describes 
 the following process : 
 
 "The glass plates are first cleaned by being well 
 rubbed with a solution of caustic potash, after which 
 they are thoroughly rinsed and polished with tripoli. 
 The next proceeding is to wax them by rubbing one 
 face over with a solution of 12 grains of beeswax to 
 one ounce of ether, this being applied by means of a 
 piece of cotton or linen cloth saturated with the 
 solution. In polishing off the excess of waxing 
 solution, care must be taken not to destroy the con- 
 tinuity of the extremely thin and almost invisible 
 film of wax which it is necessary to leave on the 
 glass to ensure the easy and complete separa- 
 tion of the film. Some operators prefer to wax 
 
78 Collotype and Photo-Lithography. 
 
 the plates by warming them to a temperature some- 
 what over the melting point of wax, then rubbing 
 one face over with a lump of the article, the excess 
 being now polished off with a piece of flannel before 
 the temperature of the glass falls below the melting 
 point of the wax. It may be mentioned that, before 
 waxing, it is as well to mark the working surface of 
 each plate by making a diamond scratch in one 
 corner. 
 
 " A small piece of cloth, moistened with ether or 
 benzole, is now used to remove all traces of wax from 
 the edges of the plates, a margin of the width of an 
 inch being sufficient ; and it is well to paint this 
 margin with albumen and to allow it to dry. Unless 
 the edges of the plate are entirely free from all traces 
 of wax, there will be a great probability of the film 
 separating from the glasses at too early a stage, and 
 adhesion at the edges is made more certain by the 
 use of albumen. A moderately diluted solution of 
 silicate of soda may be used instead of albumen. 
 
 u The waxed side of each glass is now coated 
 with collodion containing a little castor oil ; eight 
 grains of tough pyroxyline and three drops of castor 
 oil to each ounce of mixed solvents (equal volume of 
 alcohol and ether) being a convenient preparation. 
 
 "The collodion being dry, the plates are coated 
 with emulsion. The emulsion flows very badly on 
 the collodionised surface, but by using a bow made 
 of a piece of sewing cotton stretched across an arc 
 of thin iron wire the difficulty may be readily over- 
 
Collotype and Photo-Lithography. 79 
 
 come. The thread is to be drawn over the surface 
 of the plate after the required quantity of emulsion 
 has been poured on, and it is scarcely necessary to 
 say that the glass should be supported on a levelling 
 stand. 
 
 " Plates prepared in this way are developed and 
 fixed in the ordinary manner, and when a plate is 
 dry it is sufficient to cut through the film inside the 
 edge which has been cleaned of wax, when the film 
 negative can be easily stripped off. In this case, 
 however, the film is very thin, and it is often desirable 
 to thicken it somewhat before stripping. For this 
 purpose a piece of thin commercial sheet gelatine is 
 taken, and soaked in water till it becomes quite 
 flaccid, and this is laid on the negative, care being 
 taken that no air is enclosed between them. A sheet 
 of wet paper, or of mackintosh, is now laid on the 
 gelatine film, and all excess of water expelled from 
 between the negative and the soft gelatine film by 
 stroking the upper surface of the paper, or of the 
 mackintosh cloth, with a squeegee that is to say,, 
 with a strip of indiarubber set in a wooden handle. 
 
 " It is now easy to remove the paper or the 
 indiarubber cloth which was used to protect the soft 
 gelatine from the action of the squeegee, and the 
 plate can be set up to .dcy. When dry, the film is, 
 cut through within the border from which the wax 
 was cleared off, and the film will separate readily ; 
 but should there be any tendency towards a too early 
 separation, owing to the contractile force of the fresh. 
 
80 Collotype and Photo-Lithography. 
 
 thickness of gelatine, the edges of the plate may be 
 bound with strips of gummed paper." (Photographic 
 News.) 
 
 Stripping Ordinary Gelatine Plates. Any 
 make of dry plate may be stripped by the following 
 method : The plate is coated with strong tough 
 collodion upon the gelatine side ; as soon as the 
 collodion has set, it is plunged into cold water and 
 washed until all greasiness disappears. In the mean- 
 time, a piece of " flexible support," as used in carbon 
 printing, is carefully waxed by rubbing upon its sur- 
 face a solution of turpentine 140 cc., beeswax 2 gm., 
 resin 6.5 gm. This should be applied evenly by 
 means of a piece of flannel, the solvent allowed to 
 evaporate, and the waxed surface polished with a 
 -second piece of flannel. The support should then 
 be placed in cold water and allowed to become quite 
 flexible, in which state it may be used at any time. 
 Remove the negative from the clean water, and place 
 in a bath of methylated spirits 150 cc., glycerine 3 cc., 
 water 30 cc., hydrofluoric acid 3 cc. An ebonite, 
 .guttapercha, or lead dish should be used to contain 
 this solution, with which the fingers should come in 
 contact as little as possible. The film should be 
 watched narrowly, and when loose upon the glass- 
 but not actually detached the plate, still bearing 
 the film, should be placed in a bath of clean water, 
 well washed, and all surface moisture absorbed by 
 careful blotting. Take the flexible support from the 
 water in which it has been standing, and without 
 
Collotype and Photo-Lithography. 81 
 
 removing any adherent moisture, carefully lower it 
 upon the film, which is still resting upon its original 
 glass plate, squeegee it into contact with the negative 
 film, avoiding air bubbles, place under a weight, and 
 allow to stand for ten minutes or a quarter of an 
 hour. The film will then be found to adhere to the 
 flexible support, and may be readily removed from 
 the glass. It should be allowed to dry spontaneously 
 upon the support, no attempt being made to remove 
 the film until it is " bone " dry, when it will readily 
 part with the temporary support, remain perfectly 
 flat, and may be printed from either side with per- 
 fectly satisfactory results. Should any of the waxing 
 solution remain on the surface of the film, it may be 
 removed by the careful application of a little turpen- 
 tine applied on a small linen pad. Do not use 
 methylated spirit for this purpose, as it may cause 
 the film to "buckle." Any stripped films may be 
 conveniently preserved and kept flat between the 
 leaves of a book. 
 
 The Powder Process is one of importance for 
 reproducing and, at the same time and at one opera- 
 tion, reversing negatives, but for some reason is far 
 more resorted to upon the Continent than in England, 
 where few only have been able to thoroughly master 
 it. Failures are usually attributed to changeability 
 in the climate, but, although success is by no means 
 uniform, it is a thoroughly workable process. The 
 basis is a chromated solution of gum arabic, with 
 which a plate is coated, dried, and in a thoroughly 
 
82 Collotype and Photo-Lithography. 
 
 dry condition exposed to the light under a negative. 
 The greater the extent to which the light acts, the 
 smaller will be the amount of moisture the coating of 
 the plate will absorb when exposed to a damp atmos- 
 phere. If the surface of the plate be now dusted 
 over with a fine powder, as drop black, or graphite, 
 the greater the amount of moisture certain parts of 
 the film have absorbed, the greater will be the amount 
 of colour such parts will retain, and so exactly re- 
 produce the light and shade of the original negative. 
 Simple as this process reads, the difficulties must not 
 be underrated, and the operator will probably find 
 plenty of opportunity for the exercise of his patience 
 and ingenuity. A consideration of the process as 
 just described will show that a plate which has only 
 been subjected to a short exposure will, on dusting 
 over and development, be found to exhibit greater 
 density than one that has received a longer exposure, 
 a careful adjustment of which will give to the opera- 
 tor great control over the density and characteristics 
 of the reproduced negative, a power certainly too 
 important to be overlooked. A reliable formula for 
 the preparation of a gum-chromate solution for this 
 process is due to Dr. Leisegang : 
 
 Rainwater i litre. 
 
 Dextrin or glucose ... ... ... ... ... 50 gr. 
 
 Gum arabic ... . .. ... ... . . 50 gr. 
 
 Honey 10 gr. 
 
 White sugar 20 gr. 
 
 Glycerine .. ... 5 gr. 
 
 Cold saturate solution of bichromate of ammonia 100 gr. 
 
Collotype and~ Photo-Lithography . 83 
 
 which, after careful filtration, is poured over a well 
 cleaned and dusted glass plate. After draining a little 
 by standing on blotting paper, dry over a spirit lamp, 
 and place, while still warm, under a negative in the 
 printing frame one minute in the sun, 10 to 20 
 minutes in the shade, is about the necessary ex- 
 posure. As previously mentioned, the shorter the 
 exposure, the denser will be the resulting negative, a 
 result at variance to any other photographic printing 
 operation. To develop the picture the glass plate is 
 placed, coated side upwards, upon a sheet of clean 
 white paper, then, with a soft camel-hair brush, dust 
 over the picture some very finely-ground Siberian 
 graphite, working the same backwards and forwards 
 over the plate until the necessary strength is attained. 
 If the picture should develop too quickly, and take 
 the colour all over, the cause is under exposure ; 
 should the powder adhere unevenly, or the picture 
 present a smudgy appearance, the coating must have 
 absorbed too much moisture, and must be again 
 warmed before further development. This precau- 
 tion is particularly necessary during the winter 
 months. If a prolonged development be necessary, 
 and after continuous dusting a picture lacking in 
 contrast be the result, it is occasioned by over ex- 
 posure. On completion of the development the 
 picture should be finally and carefully dusted with a 
 soft brush to remove the superfluous powder, coated 
 with a thin plain collodion, and placed in water, 
 which should be frequently changed, until it fails to 
 
84 Collotype and Photo-Lithography. 
 
 show any trace of yellowness. The plate should be 
 afterwards retouched and varnished. 
 
 Negative Films have now been before the 
 public some time, and have been considerably used 
 as reversed negatives by printing with the back of 
 the film in contact with the plate. The four 
 principal varieties are, in the order of their intro- 
 duction ist, Eastman's ; 2nd, Froedman's ; 3rd, 
 Pumphrey's. 
 
 Eastman's Stripping Film consists of a sub- 
 stantial paper coated with a layer of soluble gelatine, 
 upon which is spread a coating of insoluble gelatine 
 emulsion ; they may be exposed in contact with a 
 sheet of glass in an ordinary dark slide in the film 
 carriers or on the roller slide. There are no special 
 precautions necessary in the development, except 
 that no alum may be used previous to stripping. 
 For use as reversed negatives the ordinary opera- 
 tions are greatly shortened and simplified. A sheet 
 of plate glass is coated with collodion, allowed to 
 set, and then placed in a .dish of cold water until all 
 greasiness has disappeared. After fixing and washing, 
 the negative, still supported upon the paper, is placed 
 over the collodionised plate in the same dish, and the 
 two brought out face to face. Upon the back of the 
 negative paper place a piece of blotting paper, cover 
 it with a sheet of oiled paper as used in copying 
 letters and apply the squeegee ; place a dry sheet of 
 blotting paper upon the back of the film, cover it 
 with a sheet of glass or other flat surface, upon 
 
Collotype and Photo-Lithography. 85 
 
 which place a weight. In fifteen minutes the plate 
 may be placed in warm water about 130 F. and 
 in a short time the paper backing will float off. By 
 gentle washing with hot water remove the soluble 
 gelatine from the film resting upon the glass, and 
 place the negative aside to dry. It is then complete,, 
 and reversed. 
 
 Froedman's Films consist entirely of gelatine, 
 require no stripping, and may be printed from either 
 side. The film is somewhat difficult to handle in 
 the developer, and has to be dried by spirit. One 
 feature against their employment in Collotype is a 
 yellow stain, which probably arises from the bi- 
 chromate with which the film is hardened, and 
 although more apparent where the negative is pro- 
 tected by the rebate of the dark slide, it undoubtedly 
 pervades the whole picture. 
 
 Pumphrey's Lifting Films are the latest and 
 best of a series of films introduced by the same 
 maker. They consist of a basis of paper coated with 
 a waterproof varnish on one side, upon the other 
 being spread an indiarubber coating possessing 
 considerable adhesive power ; to this is attached the 
 gelatine film proper, which consists of two layers, 
 one of plain gelatine, and the other the sensitive 
 emulsion. The films should be exposed in the 
 camera between two glass plates, and the spring of 
 the dark slide should be of considerable strength to 
 insure flatness of the film, and consequent sharpness 
 of the image. The films during development may 
 
86 Collotype and Photo-Lithography. 
 
 be treated exactly as an ordinary plate, the manu- 
 facturer recommending Beach's developer. When in 
 the bath they seem little liable to damage, and may 
 be handled with great freedom and facility. Upon 
 completion of the development, fixing, and washing, 
 the paper backing or support is attached by means 
 of paste to a substantial and smooth card. Asa 
 precaution, not always necessary, but usually ad- 
 visable, against the film prematurely separating from 
 its support, around the edges gummed paper strips 
 may be attached to the card, and allowed to extend 
 over the edges of the gelatine film to the extent of 3 
 mm. When dry the film may be varnished, and after- 
 wards lifted from its support by first cutting through 
 the gelatine and passing the blade of the knife round 
 the edges between the film and the temporary paper 
 backing, the latter remaining attached to the card. 
 The two are by these means readily separated, and 
 the resulting negative film may be printed from 
 either side without disadvantage, and is of sufficient 
 .strength to withstand a considerable amount of 
 .rough handling. 
 
 Other Methods of Reversal. There are 
 processes of copying, usually by first producing a 
 transparency and from that again a negative. If 
 the wet process is used throughout, a copying camera 
 is essential in both stages. Should dry plates, how- 
 ever, be used, the transparency may be produced in 
 the camera and the negative by contact in a printing 
 frame, or vice versa, or both may be produced by 
 
Collotype and Photo-Lithography. 87 
 
 means of the camera. If the transparency be pro- 
 duced by the carbon process a negative may then be 
 made from it by contact, and the necessary reversal 
 will be brought about without the use of the copying 
 camera. 
 
88 Collotype and Photo-Lithography. 
 
 CHAPTER VIII. 
 
 PRINTING IN THE PRESS. 
 
 THE etching or damping and rolling-up of the 
 Collotype plate presents difficulties which are 
 greater even than those met with in the preparation 
 of the plate. These remarks also apply with equal 
 force in photo-lithography, and whoever stops at the 
 preparation of the plates or the photo-lithographic 
 transfer, and leaves the subsequent operations to be 
 performed by another, should not be considered 
 either as a collotypist or photo-lithographer. The 
 whole success depends upon a succession of apparent 
 trifles ; many errors it is impossible, or at any rate 
 difficult, to rectify, and great care should be taken 
 that nothing is overlooked, or from some trivial cause 
 the whole may result in failure. 
 
 Firstly, remove all adherent matter from the 
 back of the plate, as the smallest amount of dried 
 gelatine, particle of grit or other hard matter will 
 suffice to cause the fracture of the strongest glass 
 plate on the first application of pressure. 
 
 The Etching or Damping Solution in most 
 common use consists of a stock solution of five parts 
 water, one part liquid ammonia, three parts 
 glycerine, and one-tenth part of nitrate of lime. 
 
Collotype and Photo-Lithography. 89 
 
 For use add five or six parts of this solution to 
 ico parts of water, sufficient of this being used to 
 well cover the plate when placed in a clean dish. 
 Another reliable formula is one litre glycerine, 600 cc. 
 water, chloride of sodium three grammes. Plates 
 may be immersed in these solutions for a time ex- 
 tending from ten minutes to'five hours, or they may 
 be well flooded with it, wiped off, and dried with 
 blotting paper. 
 
 The press having been examined, oiled, and put 
 in thorough working order, the next consideration 
 will bs 
 
 Fixing the Collotype Plate, which may be 
 performed in several ways. Immersing the plal e in the 
 etching fluid precludes the old method of cementing 
 it on with plaster of Paris, or glue and whitening, 
 but it may be fixed by adhesion to a bed of glass or 
 a polished iron plate, or a special and somewhat 
 complicated frame may be procured for securing the 
 thick printing plate by means of adjustable clips 
 secured by screws. Should the printing surface be 
 upon a thin glass adhesion alone will be found 
 sufficient, a few drops of water causing the printing 
 plate to adhere to the thicker glass plate underneath. 
 This method has the disadvantage that it is most 
 difficult to ensure the position of the plate being in 
 keeping with the mask on the frame. Should the 
 mask be placed directly upon the gelatine surface 
 of the plate it will not last many impressions without 
 either tearing or causing damage to the surface 
 
go Collotype and Photo-Lithography. 
 
 through the formation of creases or wrinkles. If the 
 picture has to be trimmed without margin, and 
 mounted either with or without varnish the mask- 
 ing is altogether unnecessary. The preparation of 
 the ink and rollers should next be proceeded with. 
 Supposing the work in hand to be one of a simple 
 character say the reproduction of an impression from 
 a copperplate in black take a piece of the best chalk 
 ink about the size of a hazel nut, in an unthinned con- 
 dition, as supplied to the printing trade, and with an 
 iron spatula or palette knife spread it upon the inking 
 slab. Add one-quarter the amount of middle varnish 
 (refined and odourless), one drop of olive oil, and one 
 or two drops of best French turpentine, incorporate 
 thoroughly by means of the palette knife, divide, and 
 apply one-half to the roller. The next operation is 
 the important one of 
 
 Distributing the Ink. A really good leather 
 roller, the handles of which should be encased with 
 easy fitting leather covers, is most suitable for the 
 purpose. The ink, by careful manipulation of the 
 roller, should be gradually distributed over the entire 
 surface of both roller and slab in a perfectly even 
 and regular manner. Should any small lumps be 
 observable upon either surface they should be care- 
 fully removed with the palette knife and the rolling 
 and distributing again proceeded with, as on careful 
 attention to this matter the excellence of the resulting 
 print greatly depends. The printing plate being 
 well secured, its moistened surface should be very 
 
Collotype and Photo-Lithography. gi 
 
 -evenly dried. This is best effected by means of a roller 
 covered either with fine cloth or washleather, or a 
 fine soft linen cloth may be used as a substitute. 
 
 Rolling up. Apply the inking roller with light 
 pressure to the nearest edge of the plate, and roll 
 -backwards and forwards over its surface several 
 times ; an experienced printer will at once perceive 
 .the condition of the surface. For the first inking a 
 stiffish ink should be used, as the plate will not then 
 ;so readily become dirty. By repeated rolling in 
 different directions, and what is of equal importance, 
 with varying pressure, endeavour to distribute the 
 ink with perfect evenness, and with a view of pro- 
 ducing a clear and vigorous inking, which will yield 
 a similar perfect impression. It should be remem- 
 bered that 
 
 1. A slow rolling with heavy pressure deposits 
 ink on the plate ; and 
 
 2. Light and quick rolling removes the ink from 
 the print layer. 
 
 By modifying the treatment of the plate, and varying 
 the application of the roller and damping solution, 
 .an experienced printer will demonstrate his power of 
 producing from the same plate flat, weak, and un- 
 satisfactory impressions, or prints as clear and 
 vigorous as may be desired. The first application 
 of the ink having been made with a leather roller, it 
 should be distributed, and the half-tones improved 
 by the application of a smooth roller, preferably of 
 glue composition. Without this second inking, it will 
 
Q2 Collotype and Photo-Lithography. 
 
 be found impossible to produce the highest lesultsin 
 half-tone. 
 
 The Second, or Composition Roller, must be 
 lightly charged with ink considerably thinner than 
 that applied in the first instance, the remarks con- 
 cerning the pressure applied to the leather roller 
 applying with equal force in this case. By light, 
 quick rolling, the ink is partially removed from the 
 plate, while heavier pressure and slower movement 
 will deposit ink and strengthen the shadows. 
 
 When the inking is complete, the frame with the 
 mask is placed in position. The printing paper, 
 which may be either strong, well-sized letter-paper, 
 thin cardboard, or the paper known in the trade as 
 " dull enamel," cut to a suitable size, is adjusted over 
 the mask, and backed with a couple of thicknesses'of 
 smooth paper. This again is covered, with the tym- 
 pan attached to its frame. Push the bed of the press 
 so far under the scraper that the latter, when pressure 
 is applied, will nip the plate about one centimetre 
 from the commencement of the picture. This 
 position has to be ascertained by trial before cover- 
 ing with the second or tympan frame. 
 
 The Scraper being regulated so that it will give 
 a sufficient pressure, pass the bed quickly through 
 the press to the extent necessary to produce a com- 
 plete impression. The length of traverse of the bed 
 during printing can on most presses be regulated by 
 side screws, or the tympan may be lightly marked. 
 After releasing the pressure, the bed is withdrawn, 
 
Collotype and Photo-Lithography. 93 
 
 the tympan and masking frames thrown back, and 
 the printing paper cautiously raised by one corner. 
 It often adheres slightly to the printing surface, and 
 this is usually an indication of a good plate. The 
 adhesion may, however, at times be so strong as to 
 tear the paper, or, in the case of enamel paper, 
 remove the chalk coating. As previously mentioned, 
 the scraper should be selected of a width somewhat 
 exceeding that of the picture, but never exceeding 
 that of the glass plate. It may be left plain and 
 moderately sharp, or covered with leather. 
 
 Damping the Plate between each impression 
 will usually be unnecessary, providing a good sample 
 of gelatine is used, and the damping solution contain 
 a sufficient quantity of glycerine. In cases where the 
 Collotype plate has been over exposed, or the subject 
 be one which requires an absolutely white background, 
 damping between each impression will be absolutely 
 essential. Where it is omitted for any length of time, 
 the whites of the pictures will always be more or less 
 degraded or tinted. Should the early impressions 
 not be satisfactory, patience should be exercised, and 
 by careful treatment with the roller or rollers, and 
 care in the damping, favourable results will often 
 ensue after the first few impressions have been pulled. 
 Only from actual damage to the print layer, or ex- 
 cessive over exposure in the copying frame, need the 
 plate be placed aside as in a hopeless condition. The 
 beginner should guardparticularly against mechanical 
 damages in damping; drying and rolling. Litho- 
 
94 Collotype and Photo-Lithography. 
 
 graphers are inclined to treat the delicate printing 
 surface with the same vigour and energy that they 
 would apply to the more substantial lithographic 
 stone to which they are accustomed. 
 
 The following directions from " Kleffel's Manual 
 of Photography" are to be recommended in printing 
 line subjects, particularly in "glass" printing direct 
 from the negative: "The chromated layer of gelatine 
 must have been submitted to a sufficiently long ex- 
 posure to ensure it taking the ink over the whole 
 surface. For the first rolling in of the plate, the ink 
 should be composed as follows : White wax, 45 parts; 
 middle varnish, 5 parts; gum elemi, 15 parts; litho 
 ink (about 55. per lb.), 20 parts. 
 
 " After the plate has been thoroughly rolled in 
 and blackened, it must be rubbed with a piece of 
 unbleached muslin, previously saturated with the 
 following solution : 30 parts of ammonia and oxgall 
 (about equal parts), 30 parts gum arabic, go parts 
 water, until the picture develops perfectly clear. 
 Dry with a clean piece of muslin, and roll in for the 
 printing proper with ordinary thin copper plate print- 
 ing ink. Plate paper, similar to that used in printing 
 from the copper plate, is most suitable." 
 
 When printing operations are complete, the 
 rollers, printing plates, and inking slabs should be at 
 once cleaned, as the varnish colours soon harden and 
 create difficulties. 
 
 Cleaning Leather Rollers without damaging 
 them requires considerable practice. They are 
 
Collotype and Photo-Lithography. 95 
 
 always scraped with a clean knife, and the operation 
 should be performed in one direction, to ensure which 
 it is advisable to mark one of the roller handles. 
 Leather rollers not in constant use, before being put 
 aside, should have their surfaces carefully and 
 thoroughly rubbed over with tallow, which must, of 
 course, be scraped off before the roller is again used. 
 
 Cleaning Composition and Indiarubber 
 Rollers should not be effected by means of scrap- 
 ing, but their surfaces should be cleaned with tur- 
 pentine, applied with a linen rag free from lint. 
 
 Cleaning the Plates. Turpentine is used to 
 free the surface from every particle of ink, and after 
 the thorough evaporation of the spirit, the plates 
 should be well washed in water to remove all trace 
 of the damping solution, dried, and stored in a cool 
 place. It is sometimes a matter of difficulty to 
 remove ink from Collotype plates that have been 
 printed from, but a simple method is to pour over 
 the plate as in developing a collodion picture 
 some lukewarm water. This will dissolve a thin 
 layer of gelatine, and enable one to at once proceed 
 with the work. 
 
96 Collotype and Photo -Lithography. 
 
 CHAPTER IX. 
 
 FINISHING AND VARNISHING COLLOTYPE PRINTS. 
 
 IT) ETOUCHING Prints. Under the above 
 
 1 V heading Leon Vidal, in his work " Traite 
 Pratique le Phototypie," gives the following direc- 
 tions, which I reproduce from the " Photographic 
 Archives." Even with the utmost possible care in 
 the preparation of the printing surfaces there will be 
 required in most impressions a little retouching, if 
 only to hide a few white spots. In large orders this 
 cannot be carried to the extent it is in silver prints. 
 It happens in printing that particles of dust find th ir 
 way to the plate, and cause either light or dark 
 spots in the impressions ; the former are covered 
 by touching with ink, the latter are removed with 
 the erasing knife, and the white spot resulting from 
 the operation is toned down with ink. This spotting 
 is quickly performed. The paper being dull a 
 colour should be used containing only a small pro- 
 portion of gum ; it will then be invisible. Prints 
 which it is intended to varnish should not be spotted 
 until they have been sized, unless printed upon a paper 
 already impervious to the varnish. The colour most 
 suitable of all is the actual printing ink thinned with 
 turpentine, by using which the trouble is avoided of 
 
Collotype and Photo- Lithography . 97 
 
 mixing any special colour to match the tone of the 
 impression, as the two colours are necessarily 
 identical. Another advantage gained by adopting 
 this method is that the spotting may be completed 
 before sizing, as the aqueous solution of gelatine 
 will not cause it to run. For impressions in pure 
 black the lithographic chalk is probably the best 
 medium for correcting proofs, as the colouring 
 matter will be found to well harmonise with the 
 .general appearance of the picture. A blacklead 
 pencil, on the other hand, is quite unsuited for the 
 purpose on account of the highly metallic appear- 
 ance visible wherever the pencil has been applied to 
 the print. Retouching or spotting should not extend 
 beyond the removal of light and dark spots ; the 
 correction of larger faults should not be entertained, 
 but a fresh printing surface produced. Faults present 
 in the original negative should be carefully retouched 
 and removed or reduced as far as possible. Should 
 the white margins of the picture become soiled by 
 contact with the inky mask or by finger marks, they 
 may be cleaned with indiarubber ink eraser. The 
 backs of impressions may also be cleaned in the 
 same manner. 
 
 When copies have to be mounted on cardboard 
 they may be either left with a mat surface or 
 varnished. In the first case, the edges are trimmed, 
 and they are then mounted u^on the cardboard 
 mounts. If the latter have been previously damped 
 they will retain their flatness. 
 
98 Collotype and Photo-Lithography. 
 
 Rolling or Burnishing must not be done until 
 the prints have completely dried, or the picture may 
 be torn from the mount. 
 
 Sizing and Varnishing. Prints to be var- 
 nished may be printed on prepared or sized paper, 
 and in such cases may be at once varnished. If, on 
 the contrary, the paper is not sized, they require a 
 special preparation, as follows : A 10 per cent, 
 solution of gelatine is laid on with a broad camel- 
 hair brush, avoiding air bubbles and streaks. After 
 a little practice this operation will be found both 
 easy and rapid. The sized pictures are pinned in 
 pairs back to back on a wooden frame, to which 
 strips of cork are attached ; when the prints are 
 quite dry the operation of varnishing may be pro- 
 ceeded with. A good varnish, probably the best for 
 the purpose, which possesses the double advantage 
 of remaining colourless and setting very hard, con- 
 sists of a solution of 15 parts of white (bleached) lac 
 in io~: parts of wood spirit (vegetable or wood 
 naphtha). On dissolving the shellac it will be found 
 that the solution is clouded on account of the sus- 
 pended fatty matter, the removal of which is always 
 desirable ; the varnish will then filter more rapidly 
 and give a more glossy coating. By adding powdered 
 lime three parts of the solution may be decanted 
 clear, and the remainder may also be used after 
 filtration through felt. Or if to three parts of varnish 
 one part of benzine or petroleum ether be added, the 
 solution will resolve itself into two layers, and the 
 
Collotype and Photo-Lithography. 99 
 
 upper one, which will contain the fatty matter, may 
 be poured off. The varnish is best applied by means 
 of a ball or dabber, care being exercised to avoid air 
 bubbles ; the print is next placed in 
 
 The Drying-box (see fig. 8), which is a four- 
 
 sided tin box I m. long by 0*25 m. high. A gas- 
 pipe, perforated with small holes drilled about 6 to 
 8 cm. apart, runs through the upper part of the box, 
 the front of which is open to two-thirds its height. 
 A plate, finely perforated, divides the upper third 
 from the lower two-thirds, and forms an inner 
 division, through the upper of which the gas-pipe 
 passes. The flat perforated division is hinged to 
 allow of being opened for the purpose of igniting the 
 gas. The pictures placed on the bottom of the box 
 dry very rapidly, v hile the perforated division 
 prevents the possibility of the ignition of the vapour 
 of the spirit employed. With such an apparatus it 
 is possible to varnish and dry a large number of 
 prints in a very short time. 
 
 Sizing may be Avoided if each picture, after 
 well drying, be dipped into the following solution : 
 Water 500 g., borax i3Og., white shellac icog., 
 
Collotype and Photo-Lithography. 
 
 carbonate of soda 6g. The borax and carbonate of 
 soda are dissolved in boiling water, and the powdered 
 shellac then added in small quantities ; when solution 
 is complete carefully filter and allow to cool. The 
 impressions, two and two, back to back, are pinned 
 on frames, dipped in the varnish, and afterwards 
 dried. By this procedure a shellac coating is given 
 to the surface only of the print ; there is no gelatine 
 substratum to soften through atmospheric influences, 
 and so crack and destroy the layer of varnish. In 
 winter the temperature must be kept high, and the 
 solution should bs heated 15 to 20 C. 
 
 Parchmentising to a slight degree may also 
 be adopted to close the pores of the paper. Add 
 one part by volume of water to two parts of sulphuric 
 acid, allow it to become quite cold, immerse the 
 pictures for one second only, and at once wash in a 
 copious supply of clean water to which has been 
 added a small quantity of ammonia to effectually 
 neutralise the acid. The action of the acid must 
 n^t be carried too far, as it is merely necessary to 
 act on the surface. To prevent paper so treated 
 from cockling while drying, it must be put under 
 pressure or stretched upon a frame ; when quite dry 
 it has to be varnished and dried by heat. 
 
 Varnishing Enamsl Paper without previous 
 sizing is best done by means of an alkaline solution 
 of shellac prepared as follows : Place in a six litre 
 tin flask J kilo of bleached and powdered shellac, 
 pour over it ij kilo of alcohol and ijkilo of strongest 
 
Collotype and Photo-Lithography. 101 
 
 ammonia. In the course of a few days the solution 
 of the shellac will be complete, then add, with 
 constant stirring, 2 J kilo of hot water, and when cold 
 filter. It may be applied to the print with a broad 
 Blanchard brush,* and left to dry in a horizontal 
 position. The prints may also be floated on the 
 varnish for about half a minute, and then suspended 
 to dry by means cf clips. After a few minutes have 
 elapsed a piece of blotting paper should be applied 
 to the bottom edge to absorb the superfluous varnish. 
 Rolling or Burnishing must on no account 
 be attempted until the mounted prints are perfectly 
 dry, otherwise they may be seriously damaged or 
 even completely torn from the mounts. 
 
 -'' Made as follows : Take a piece of glass, say 20 cm. long by 6 or 7 cm. 
 wide, and a piece of swansdown calico the same width as the glass but only 
 6 cm. long, fold this over the one end of the glass, 3 cm. being on each side, 
 and bind round with thread or spring on a rubber band. 
 
io> Collotype and Phrto-Lithographv. 
 
 CHAPTER X. 
 
 OTHER COLLOTYPE PROCESSES. 
 
 Artotype Company, of New York, which 
 JL has acquired Obernetter's process, proceed on 
 somewhat different lines to those laid down in this 
 work, and an abstract of their proceedings is here 
 given as interesting to those about to experiment. 
 According to Bachrach, " Photographic Archives, 
 1879," p. 66, they proceed as follows : 
 
 Plates coated with Husnik's silicate of soda 
 substratum are dried rapidly in a box heated to 
 65 C. This causes the solution to coagulate, the 
 plates are dried in half-an-hour, and as it adheres 
 with great tenacity to the glass plate, the latter may 
 be at once coated with the chromated gelatine solu- 
 tion, or it may be kept till the next day. Before the 
 second coating is applied the plate is well washed and 
 allowed to dry spontaneously. The drying-box is of 
 wood, 2j feet square and 5 feet high, the entire front 
 being a large door, as shown in the sketch (fig. 9), and 
 the bottom a flat water tank about four inches deep 
 fitted with two pipes, one to allow the escape of 
 steam, and the other of use in filling the tank with 
 water. It may be heated by means of gas or a 
 petroleum lamp. After the bottom of the box has 
 
Collotype and Photo-Lithography. 103 
 
 Fig. 9. 
 
 been accurately levelled, it is covered with a few 
 sheets of blotting pap:r, on which are placed the 
 albumenised plates. Occupying the upper part of 
 the box are adjustable racks, on which other plates 
 are dried. The box is heated to 82 C., the plates 
 are levelled in their places, and just sufficient hot 
 chromatised gelatine solution poured on each to 
 spread up to the edges not more. The Artotype 
 Co. take one-third each of gelatine, isinglass, and 
 the so-called Magdebourg isinglass. Plates are 
 allowed to remain in the drying-box about 20 to 30 
 minutes, during which time the door must not be 
 opened, and particular importance is attached to the 
 high temperature, reaching even to 93 C., at which 
 the drying is completed, as it is considered by these 
 means printing plates of much finer grain are ob- 
 tained. (The Author believes the temperature given 
 is much too high, as it would be sufficient, without 
 exposure to light, to bring about a partial decompo- 
 sition.) When dry, the plates may at once be printed 
 
104 Collotype and Photo-Lithography. 
 
 under the negative. To etch the plate it is immersed 
 in a solution of 5 gr. alum in i litre of water, rinsed, 
 allowed to dry, and put in a bath consisting of 
 150 ccm. of water, I litre of glycerine, 300 ccm. of 
 ammonia, 30 g. nitrate of lime. Plates that have 
 been exposed under the negative too long are treated 
 with a solution of 20 parts of ammonia, 20 parts of 
 glycerine, and one part of Venetian turpentine ; with 
 this they are flooded. The remainder of the process 
 is very similar to that already described. 
 
 Seignior Carlos Relvas. Vidal publishes the 
 following method of procedure as that adopted in the 
 studio of this eminent Portuguese amateur collotypist, 
 where it was introduced by Jacobi : Very thick glass 
 plates, finely ground on one side, are used ; they are 
 cleaned with nitric acid, and rinsed in distilled water. 
 The drying box used is provided with iron bars, fitted 
 with adjustable screws for the purpose of accurately 
 levelling the plates. Midway between the top and 
 bottom of the box is an iron plate, underneath which 
 are fitted gas jets. The doors by which access to the 
 box is gained for the plates consists of very fine wire 
 gauze, allowing the escape of steam, but preventing 
 the access of insects. After a thorough cleansing, the 
 plates are levelled on the adjusting screws, allowed 
 to thoroughly dry, and then coated on the ground 
 side with the following solution 
 
 White of egg 1 60 ccm. 
 
 Bichromate of potassium ... ... 8 g. 
 
 Distilled water ... ... ... 480 ccm. 
 
 Glycerine ... ... ... ... 16 drops. 
 
Collotype and Photo-Lithography . 105 
 
 To which is added sufficient ammonia to give the 
 liquid a pale yellow tint, somewhat less being used 
 where a hard negative is to be employed. This 
 substratum is filtered, and the plates afterwards 
 coated and placed upon the levelling screws in the 
 drying box, which is heated to a regular temperature 
 of 40 C. In about two hours the plates will be dry, 
 and are then placed, coated side downwards, upon a 
 black cloth, the back of the plate being exposed to 
 diffused light for half-an-hour. It is again placed in 
 the drying box, and the second coating, as follows, 
 applied 
 
 Gelatine .., ... ... ... 27 g. 
 
 Water ... . . ... ... ... 400 ccm. 
 
 Bichromate of potassium 9 g. 
 
 Preparation A.. ... ... ... 15 ccm. 
 
 Preparation B ... .. ... ... 15 ccm. 
 
 Ammonia a few drops. 
 
 The preparations A and B are as follow : 
 
 A. Chloride of sodium i g. 
 
 Water... ... ... ... ... 500 ccm. 
 
 B. Sulphate of alumina i g. 
 
 Water... ... ... ... ... 100 ccm. 
 
 To each square decimetre of surface should be 
 allowed 2 ccm. of the above solution. The plates 
 are replaced in the drying box, which is heated to 
 45 or 50 C. They should be dry in three hours, and 
 are then ready for printing under a negative in the 
 copying frame. They are afterwards well washed in 
 filtered water, and allowed to dry spontaneously in a 
 dust-proof situation. In two or three days the print- 
 ing may be proceeded with, the surface having been 
 
io6 Collotype and Photo-Lithography. 
 
 softened by allowing the plate to stand for seven 
 
 hours in the following solution- 
 Glycerine ... ... ... ... 500 ccm. 
 
 Distilled water ... ... ... ... 200 ccm. 
 
 Preparation C ... ... ... ... 100 ccm. 
 
 PREPARATION C. Sulphate of magnesia ... 50 g. 
 Distilled water ... ... 500 ccm. 
 
 All solutions are filtered through flannel. From the 
 face of the plate the superfluous moisture should be 
 removed \vith a sponge. A very thick glass plate is 
 fixed to the face of a lithographic stone by means of 
 glue and whiting, and adhesion is secured between 
 the face of the thick glass plate so fixed and the 
 back of the Collotype plate by means of a few drops 
 of water. The whole, so arranged, is placed upon 
 the bed of the press. Should the prints lose their 
 contrast while the printing is in progress, they are 
 lightly sponged over with a sponge dipped in the 
 last-mentioned solution. If this fail to produce 
 sufficient effect, the plate is first washed with tur- 
 pentine, and then with the glycerine solution. Care 
 should be taken to prevent the two liquids becoming 
 mixed on the plate, to prevent which different sponges 
 and drying cloths should be used. 
 
Collotype and Photo-Lithography. 107 
 
 CHAPTER XI. 
 
 FAILURES IN COLLOTYPE. 
 IN THE PREPARATION OF THE PLATES. 
 
 AIR bubbles in the albumen substratum. These 
 must either by filtration or by the aid of a 
 piece of paper be carefully removed from the solution 
 'before it is applied to the plates. The latter must 
 be well cleaned and dusted, and freed of emery 
 powder if they have been re-ground. 
 
 To Prevent Dust or other matter rising from 
 the edge of the plates by capillary attraction while 
 standing, they should be allowed to rest on clean 
 blotting paper, and preferably on one corner only. 
 
 Coating Plates. Great difficulties are ex- 
 perienced by the beginner in coating the plates with 
 the chromated gelatine": He seldom knows before- 
 hand the exact quantity required, or the temperature 
 of the solution. The latter ought to be ascertained, 
 as it is an important factor in the thickness and 
 flow of the coating ; with a solution only just warm 
 it is impossible to apply a very thin coating, while 
 the hotter the gelatine the thinner the layer. Con- 
 siderable dexterity and judgment are necessary to 
 spread an even layer of the requisite thickness, 
 which is a matter most essential to success, but, 
 
io8 Collotype and Photo-Lithography. 
 
 unfortunately, only to be mastered by actual ex- 
 perience. 
 
 Plates are not unfrequently spoiled by inclining 
 them while conveying them to the drying box, as in 
 this way the coating is frequently rendered uneven. 
 
 All solutions must be carefully filtered, and the 
 plates freed entirely from dust. The drying box> 
 particularly the lid, must be carefully dusted and 
 cleaned, but not immediately before use. 
 
 Other necessary precautions have been pointed 
 out while describing the preparation of the plates. 
 By strictly adhering to the rules laid down it will be 
 found possible, after a certain amount of practice,, 
 to avoid the pitfalls here enumerated, while with 
 regard to faults in the plates, there only remain to 
 be mentioned the consequences of drying at too high 
 a temperature. 
 
 Thick Films are extremely liable to fly off the 
 glass and damage its surface, if dried at too great a 
 heat. The thicker the film the lower should be the 
 temperature of the drying box. 
 
 Thin Films, dried at too high a temperature, 
 even without exposure to light, present a brown 
 appearance, their sensitiveness is impaired, and they 
 take too much ink over their entire surface. 
 
 FAILURES IN PRINTING. 
 
 It is generally an advantage to work the press in 
 a cool and somewhat damp apartment. 
 
 Breakage of the Plate. Notwithstanding its 
 thickness, the glass plate sometimes flies to pieces 
 
Collotype and Photo-Lithography. 
 
 on pulling the first impression. If the plate 
 foundation are perfectly level the breakage nAst 
 arise from the presence of some foreign substance^ 
 having found its way between the two surfaces. 
 
 This may occur from such a trivial matter as a 
 grain of sand, perhaps introduced between when 
 moistening the under side of the plate to secure 
 adhesion. Or traces of chromated gelatine may be 
 found attached to the under surface of the plate, 
 either of which causes is quite sufficient to account 
 for a breakage with even moderate pressure. In 
 Collotype the pressure need not be by any means so 
 heavy as in lithographic printing; it should be evenly 
 distributed, and may be moderated by placing the 
 stone or glass plate, or whatever the Collotype plate 
 may be attached to, on some comparatively elastic 
 bedding, which may consist of several layers of - 
 printing paper, thin felt, thick indiarubber sheeting, 
 or linoleum, any of which may be used. 
 
 Spotted Impressions. The plate yields un- 
 satisfactory copies covered with white spots 
 resembling drops of water. This most frequently 
 occurs at the commencement of the printing, and is 
 nearly always caused by uneven damping of the 
 surface. Old plates which have been dried very 
 often give perfect negative impressions at first. In 
 such cases, after the removal of the ink by tur- 
 pentine, soak the plate for a quarter of an hour in 
 water, to which has been added a little glycerine 
 and ammonia (see " Etching Fluid"). Dry the plate 
 
no Collotype and Photo -Lithography. 
 
 with a clean roller covered with cloth or chamois 
 leather or, as a substitute for the roller, a soft linen 
 cloth may be used and again roll in with ink which 
 has been thoroughly well distributed on the inking 
 slab. 
 
 Too Much Ink is taken by the plate over the 
 whole surface, and notwithstanding slow or rapid 
 rolling, it refuses to leave the high lights. Cause- 
 over-exposure in proportion to the thickness of the 
 layer, which is probably too thin. In such cases 
 washing with dilute solution of ammonia will often 
 improve matters. Another proceeding to be recom- 
 mended in the case of a plate taking too much ink is 
 to remove all ink by means of a sponge damped in 
 water containing a little petroleum not benzine or 
 turpentine and afterwards wash the plate with a 
 sponge containing glycerine and water. It is then 
 ready for immediate printing from, and ought to give 
 about 200 copies without further damping if the press 
 be in a moist situation. 
 
 Loss of Half-tone arises from the print layer 
 becoming too moist, when the more delicate half- 
 tones fail to print. Dry with blotting paper, and 
 immerse for five minutes in a bath of alcohol ; this 
 will take up the water, and the succeeding im- 
 pressions will be greatly improved. 
 
 Uneven Inking. It sometimes occurs, par- 
 ticularly in pictures which should show a white 
 ground, that the latter takes more ink in one part 
 than another. This usually arises from an unequal 
 
Collotype and Photo-Lithography. in 
 
 thickness of ~ the sensitive coating. The plate will 
 take most ink where the coating is thinnest, and for 
 this fault there is no remedy. 
 
 Ink Refused by the Plate. Sometimes, after 
 a few impressions have been pulled, the plate refuses 
 to properly take the ink, from the layer being too 
 thick and having been too freely moistened. Further 
 damping should be discontinued and a thinner ink 
 used, which will better take upon the deep-lying 
 shades. This fault will be found most pronounced 
 in the cases of written or printed titles to pictures, 
 and other cases exhibiting extremely dispropor- 
 tionate action of light. Therefore, when there is 
 writing to a picture, it should be shaded somewhat 
 during printing in the printing frame, or if the con- 
 trast be very violent it may fail to print entirely. 
 
 Flat Prints. After a number of satisfactory 
 prints have been produced the succeeding ones 
 become flat this fault will be especially noticeable 
 with thin layers devoid of isinglass, and in cases 
 where the negative has been too flat and lacked con- 
 trast. Dampen more frequently with dilute ammonia 
 and glycerine. 
 
 Paper Adhering to the Gelatine Those 
 layers which yield the best and most brilliant im- 
 pressions, showing plenty of contrast, which have 
 been fully printed under a vigorous negative, most 
 often exhibit a disagreeable tendency to adhere to 
 the paper in the high lights. The greater the pro- 
 portion of isinglass present in the film the more will 
 
112 Collotype and Photo-Lithographv. 
 
 this fault manifest itself, particularly with an enamel 
 paper. An application of a diluted solution of ox- 
 gall to the film, the use of a thick well-sized or 
 glazed paper, lighter pressure while printing, and 
 less frequent damping will all tend to diminish this 
 evil. Layers of this nature are extremely liable to 
 damage, and the adhesive portions will soon suffer 
 unless the greatest care is exercised. 
 
 Ink Remains upon the Plate. Through too 
 light or uneven pressure it sometimes happens, 
 especially when using a stiff ink, that the latter will, 
 after the impression has been pulled, partially adhere 
 to the darkest portions of the printing surface, par- 
 ticularly on the edges of plates deeply copied. If 
 this fault is not corrected at once, and the printing 
 allowed to proceed, these portions giving a light, 
 faulty impression will gradually increase in size, and 
 the corresponding portions of the Collotype plate 
 gradually darken. When first observed the whole 
 plate must at once be cleaned with turpentine and 
 again rolled up with thinner ink, a greater and per- 
 fectly even pressure being applied. Small faults of 
 this nature occurring on the edges of the plate can 
 be corrected after each faulty impression by means 
 of a small piece of sponge moistened with gum water 
 or with a turpentine rag. 
 
 Displacement of the Paper under the scraper 
 will create a double impression, and sometimes 
 wrinkles, the latter invariably leading to the de- 
 struction of the plate. By adopting the use of the 
 
Collotype and Photo-Lithography . 113 
 
 bridge now used in conjunction with most Collotype 
 hand presses, this fault is avoided, as the paper is 
 only in contact with the printing surface immediately 
 under the scraper. 
 
H4 Collotype and Photo-Lithography. 
 
 CHAPTER XII. 
 
 INVESTIGATIONS ON COLLOTYPE. 
 
 A UGUST ALBERT* is of opinion that it is by 
 JT\ no means a matter of indifference whether 
 bichromate of potassium or bichromate of ammonia 
 is used in the preparation of the Collotype plates ; 
 on the contrary, he believes that the latter salt 
 materially conduces to interruptions in printing, 
 
 especially in unsettled weather. The results of his 
 experiments with the two salts in the Collotype 
 
 process, and of their behaviour in combination with 
 different sorts of gelatine, are as follows : 
 
 To 1000 cc. of water are added ten drops of a 
 saturated solution of chrome alum ; this mixture, 
 after having stood for a quarter of an hour, must, if 
 shaken up, show an opalescent appearance, and a 
 slight milky turbidity ; if too much chrome alum has 
 been added, the water acquires a greenish colour. 
 The gelatine is now added, and, for about fifteen 
 minutes, kept at a temperature of 134, when the 
 chrome salt is added, stirring all the while, and the 
 temperature of the water bath raised to 150 to 
 
 * This experimentalist has evidently been confused with the late Joseph 
 Albert, of Munich, by some writers. It may be mentioned that Joseph 
 Albert, whose business is still carried on by his widow, was father of Dr. 
 Eugene Albert, known in the photographic world for his orthochromatic 
 collodion emulsion. August Albert, of Vienna, is of another family. 
 
Collotype and Photc-Lithography. 115 
 
 1 60. The temperature and time must strictly be 
 adhered to. The jelly thus prepared should be kept 
 at least ten hours in a solidified state previous to 
 using. 
 
 Hard Gelatine. Plates prepared with this, 
 show after drying, a shiny, transparent film, more or 
 less according to the quality. Such plates give hard 
 prints, and are soon used up in printing, the finest and 
 even the middle tints becoming weaker, and the 
 shadows gradually coalescing, specially in the case ot 
 short exposure and very dense negatives, and they are 
 generally useless after a few impressions have been 
 taken. If ammonium bichromate is used, together 
 with hard gelatine, then, as a general rule, it is 
 impossible to obtain more than one or two prints 
 from each plate. By washing the gelatine, these 
 inconveniences are not at all removed, no matter 
 which of the two salts has been used. 
 
 Soft Gelatine. If this is prepared with 
 potassium bichromate, then the plates will have a 
 dull but rough and untransparent film, which will be 
 found very unserviceable for printing, as the prints 
 will lack vigour ; the high lights will tone, and 
 the whole picture appear blurred. If, however, 
 ammonium bichromate is used in conjunction with 
 soft gelatine, the plates will also have a dull appear- 
 ance, but though they work somewhat better than 
 those prepared with potassium bichromate, they will 
 not be of sufficient durability, the finer tones soon 
 disappearing during printing. Therefore, neither 
 
n6 Collotype and Photo-Lithography. 
 
 hard nor soft gelatine are suitable for Collotype work, 
 as the printing operations are rendered more diffi- 
 cult. If both sorts are mixed, the results will be 
 somewhat better, but not like those obtainable with 
 middle hard gelatine, which must be accepted as 
 the most suitable kind for Collotype work. 
 
 Middle Hard Gelatine, manufactured by 
 Ferd. Friedr. Creutz, absorbs five times its own 
 weight of water at b6, without signs of disintegra- 
 tion after standing therein for thirty-six hours. If 
 prepared with it and with chemically pure potassium 
 bichromate, the plates after drying have a beautiful 
 matt surface, from which long numbers can be 
 printed without any falling off of the half tints, and, 
 if the printing is done carefully, even the details in 
 the shadows will be maintained to the last. This 
 bichromated gelatine requires also only a very small 
 amount of re-damping, reproduces faithfully the' 
 character of the negative, and the jelly can be used 
 even after a period of four days. If, however, the 
 work in hand requires a harder bichromated gelatine 
 as, for instance, reproductions of black and white 
 then the addition of a small quantity of ammonium 
 bichromate will have the desired effect ; in some 
 cases equal quantities of the bichromates of potassium 
 and ammonium. If ammonium bichromate is used 
 instead of potassium in conjunction with middle hard 
 gelatine, then the plates will acquire a shining, trans- 
 parent coating, the manipulation of which is very 
 difficult in printing, and which work too hard, being 
 
Collotype and Photo-Lithography. 117 
 
 serviceable, at any rate, for reproductions without 
 half-tint. If, however, the middle hard gelatine is 
 washed before use, it will give, when mixed with the 
 chromic salt, transparent films of insufficient 
 durability. Middle hard gelatine should there- 
 fore be used unwashed for Collotype work, and 
 mixed with chemically pure potassium bichromate. 
 
 The Production ot Grain in Collotype plates 
 takes place in the last instant of drying the plates in 
 the drying-cupboard ; it depends entirely upon the 
 larger or smaller quantity, and the consistency of 
 the bichromated gelatine used. If the latter is of 
 good quality, all artificial means for the production 
 of grain are not only superfluous, but also disadvan- 
 tageous. A larger addition of chrome salt generally 
 gives rise to the crystallisation of the salt ; chloride 
 of sodium produces plates highly sensitive to 
 moisture, but no grain ; a larger addition of chrome 
 alum gives plates which will lack vigour, and the 
 t manipulation of which, during printing, will be 
 difficult, as they ofcen will require an " after-etching," 
 so that even printing is made impossible. 
 
 To test the suitability of gelatine for Collotype 
 work, two small portions of the gelatine to be tested 
 may be made up, adding chemically pure potassium 
 bichromate to the one, and ammonia bichromate to 
 the other, and a plate prepared with each solution. 
 If both plates show a dull and untransparent coating, 
 this indicates that it is a soft gelatine ; if, on the 
 contrary, both plates appear glossy and transparent,. 
 
1 1 8 Collotype and Photo -L ithography . 
 
 then the gelatine is hard. Should it, however, be 
 middle hard, then the dried film prepared with 
 potassium will be dull, but not rough ; that with am- 
 monia, however, shiny and transparent. 
 
Collotype and Photo-Lithography. 119 
 
 CHAPTER XIII. 
 
 COLLOTYPE IN NATURAL COLOURS. 
 
 A SHORT chapter may be devoted to the 
 various suggested processes for producing 
 Collotype in natural colours, with which are asso- 
 ciated the names of Vidal, Albert, and Obernetter. 
 To give a complete resume is altogether impossible, 
 as up to the present time the inventors have only 
 published their method of procedure with very con- 
 siderable reservations, and notwithstanding the fact 
 that a great deal has been written and published in 
 current literature on the subject, little is actually 
 known. The methods of Vidal and Albert are 
 essentially alike, both being founded upon an opti- 
 chemical basis. By careful registration and printing 
 from three Collotype plates, representing fragments of 
 the same subject upon one sheet of paper, and 
 making use of inks corresponding with the three 
 primary colours, a total effect should be produced 
 which ought, theoretically, to resemble the coloured 
 original. In preparing the three negatives for 
 reproducing the three colour plates a special 
 mode of procedure must be adopted. Each of 
 the three negatives must give a resulting Collo- 
 type plate capable of retaining varying amounts of 
 ink when rolled up, according to the predomination 
 in the original of one or the other of the primary 
 
I2O Collotype and Photo-Lithography. 
 
 colours red, blue, or yellow.* This is effected in 
 the production of the negative for the red plate, by 
 making the exposure through a green glass screen, 
 while the negative intended to produce the plate 
 from which the yellow is to be printed is exposed 
 through a screen of violet. 
 
 The green screen allowing to pass so few 
 chemically active rays the exposure has to be pro- 
 longed to such an extent that gelatine bromide dry 
 plates stained with eosine must of necessity be used. 
 
 Obernetter's method is entirely different, depend- 
 ing more upon mechanical assistance of a non- 
 photographic character in the production of the 
 unlimited number of negatives he uses for producing 
 his printing surfaces, and the results more closely 
 resemble those of chromo-lithography. What par- 
 ticulars Obernetter himself has from time to time 
 communicated are here given. He first produces, by 
 the dusting-on process, as many copies of the original 
 negatives as there are colours to be reproduced. The 
 negative intended to produce the plate from which 
 the blue will be printed is obtained by a long ex- 
 posure and only slight dusting of the reproduced 
 
 * Pictures produced in the three primary colours are extremely crude. 
 Dr. Vogel has proposed a large number of negatives, using for their produc- 
 tion sensitisers corresponding with every region of the spectrum. For 
 example Napthol blue for red, cyanin for orange, rozin for yellow, and 
 fluorescein for bluish green, the ordinary sensitiveness of the plate being 
 sufficient for blue and violet, the- latter, however, being exposed through a 
 yellow screen. The images thus obtained are printed from lithographic 
 stones or Collotype plates, each of which is printed in a colour complimen- 
 tary to that part of the spectrum to which the particular plate was 
 sensitive. The greater the number of separate images produced in this way 
 the more complete will be the reproduction of the various shades in the 
 original, and the more pleasing the resulting print. 
 
Collotype and Photo-Lithography. 12 1 
 
 negative. That intended to reproduce the plate for 
 the non-actinic colours yellow or brown shoukiQ^ . 
 correctly exposed and dusted in ; while that intended 
 for the red should be subjected to a shorter expos^e /^/ 
 and more vigorous dusting. By retouching, the:^/^ v^ 
 densities of the various negatives may be modified 
 by strengthening them in parts, other portions are 
 stopped out, and the negatives so manipulated that 
 they will produce plates capable of giving impres- 
 sions when printed in their proper colours giving 
 .a facsimile reproduction of the original work. Much 
 will depend upon the artistic qualifications of the 
 operator, who may, by extending the number of plates, 
 iinally produce copies of considerable artistic value. 
 Hosch, of Munich, has patented a process in 
 which the same result is attained in a somewhat 
 different manner. A negative is produced, and from 
 that a Collotype plate from which a number of 
 impressions are taken equal to the number of print- 
 ing desired or necessary in the finished chromo- 
 collotype picture. Each print has certain portions 
 painted over in a neutral tint, such portions depend- 
 ing upon the colour of the ink in which it is 
 intended to print the corresponding plate. Other 
 portions are stopped out white in the print, or black 
 in the negative, and from the prints so treated a set 
 of negatives are taken; these are utilised for the 
 production of a set of Collotype plates, which, printed 
 from in suitable colours, yield impressions of great 
 excellence. i 
 
122 Collotype and Photo-Lithography. 
 
 CHAPTER XIV. 
 
 MAGIC PRINTS. 
 
 TO Professor Husnik (to whom collotypists 
 are greatly indebted for so many unselfish 
 publications), we owe the orgination of this interest- 
 ing method of producing " magic " prints. It is 
 founded on the reaction well known to chemists that 
 two substances, each colourless in itself, when mixed, 
 enter into fresh chemical combinations and produce 
 other substances of intense colour. Herschel and 
 Hunt made use of many of these reactions, both to 
 develope the invisible image, and to give to others, 
 already visible a more agreeable colour or tone. 
 Impressions other than those in fatty ink may be 
 obtained from the Collotype plate as in the process 
 patented by Edwards by means of colour, soluble 
 in water, to which the addition of a small amount of 
 gum has been made. In such cases it will not be 
 those portions of the layer which have been rendered 
 insoluble by the action of light which will give the 
 impression (as it would if ink were used) but on the 
 contrary, the unexposed parts, or those which remain 
 soluble. On this account the resulting print will be 
 a negative, and to obtain a positive, the printing must 
 take place under a positive. If a Collotype plate so 
 
Collotype and Photo-Lithography. 123 
 
 produced be damped with a linen rag which has 
 been moistened with an aqueous solution of a salt 
 readily absorbed by gelatine, and which will produce 
 in combination with a second solution an intensely 
 coloured compound (the use of the ink roller being 
 entirely omitted), the impression on the printing 
 paper will be almost or even entirely invisible until 
 brought in contact with the second solution, when 
 the picture will be immediately developed and 
 rendered visible. For instance, dampen the plate 
 with an aqueous solution of red prussiate of potash, 
 surface dry it, print upon paper, allow to dry 
 thoroughly, and place upon a solution of proto- 
 sulphate of iron, when the picture will immediately 
 appear of an intense blue colour. Solutions of 
 bichromate of potassium or nitrate of silver will pro- 
 duce brown images ; the former developed with extract 
 of logwood, alazarine or sugar of lead, all produce 
 different colours. Not only is this process interest- 
 ing, applied in the manner already described, but it 
 is of use in calico printing. Care must however be 
 exercised in the selection of a suitable solution for 
 damping the plate, as many salts would tan the 
 gelatine layer, and such are of course utterly unsuited 
 for the purpose. Among the mordants in common 
 use, salts of tin, alum, iron, &c., may be mentioned 
 as exercising a hardening influence upon gelatine, 
 and therefore useless for moistening the layer. There 
 remain, however, many others which produce no 
 damaging effect upon the plate, and at the same 
 time produce useful colours. 
 
124 Collotype and Photo-Lithography. 
 
 CHAPTER XV. 
 
 PHOTO " GLASS" PRINTING.* 
 
 THERE remains to be mentioned another varia- 
 tion of the Collotype process known under 
 the above vague title, the distinctive characteristic 
 of which method of preparing the plate is that the 
 negative is taken upon a sheet of glass sufficiently 
 thick to stand the necessary pressure in printing 
 when converted direct into a Collotype plate. After 
 the completion and drying of the collodion negative 
 it is coated upon the film side with the chromated 
 gelatine solution, dried in the drying-box, laid face 
 downwards upon a black velvet surface, and exposed 
 through the back of the glass. The first publication 
 of this method of preparing plates emanated from 
 the State Printing Works at Berlin, and the fol- 
 lowing is an outline of the method there practised ; 
 "it is scarcely necessary to state that it is only avail- 
 able for line subjects. The collodion used in the 
 preparation of the negative should be one capable of 
 producing clear, hard negatives entirely free from 
 fog ; probably some modification of the dark slide 
 may be necessary to enable it to receive a plate of 
 
 * This process has never been practised in this country so far as I am 
 aware. TRANS. 
 
Collotype and Photo-Lithography. 125 
 
 sufficient strength to stand printing from. The 
 collodion negative being completed it is flooded with 
 the chromated gelatine as applied to Collotype 
 plates, dried, and exposed through the negative until 
 the print layer has assumed a dark brown colour ; it 
 is well washed in cold water and damped before 
 printing by an application of gum water containing 
 a little ox-gall ; this is done to facilitate the pro- 
 duction of perfectly clear impressions. The same 
 end may be attained by the application of dilute 
 ammonia and glycerine. The author has experi- 
 mented for several years in the same direction with 
 the object of producing heliographic printing plates 
 in copper, for which purpose this method of pro- 
 ducing reliefs in gelatine is well suited. From the 
 negative printing plate described, which is treated in 
 all respects as a Collotype plate, impressions may be 
 taken upon transfer paper, and transferred to stone 
 or zinc. Before coating the negative with the 
 chromated gelatine the plate should be allowed to 
 dry. In consequence of printing from the back the 
 lines will always be slightly wider than the original, 
 to meet which difficulty Brandt has proposed putting 
 the negative, when fixed and washed, but still wet, 
 into a weak solution of chromated gelatine, which 
 will, if a suitable collodion has been employed, 
 entirely penetrate the latter. This variation appears 
 worthy of commendation ; it is, therefore, here given 
 in the abstract : " Having produced a negative in 
 the usual manner, on a plate which has been lightly 
 
126 Collotype and Photo-Lithography. 
 
 but carefully albumenised, and having fixed and 
 washed the same, it is placed for five minutes in a 
 solution prepared as follows : Allow 45 parts of 
 gelatine to swell in water, and pour off the surplus, 
 add 50 parts of distilled water, and apply sufficient 
 heat to completely liquify the gelatine, adding a 
 solution of 5*5 parts of bichromate of ammonium in 
 100 parts of water, and heat again to 60 Reamur. 
 With plates of large size the solution may be poured 
 over the plate, and it may be necessary to repeat this 
 operation several times to ensure an even and 
 sufficient coating. Immediately previous to the 
 application of the chromated layer the negative 
 should be rapidly washed over with warm water. A 
 sufficient quantity of the chromated solution must be 
 allowed to remain upon the plate, and the latter 
 warmed in a horizontal position over a spirit lamp. 
 When steam arises the plate has to be held in a 
 perpendicular position for a minute, restored to its 
 horizontal state, and again warmed until the coating 
 of the plate is quite dry, care being taken that 
 at no time the plate is so heated that it becomes 
 unpleasant when placed upon the hand. Place the 
 plate face downwards upon a black support, print 
 until the fine lines are plainly visible, when the plate 
 may be washed and further treated as in Collotype." 
 
Collotype and Photo -Lithography. 127 
 
 CHAPTER XVI. 
 
 ALLGEYER'S COLLOTYPE PROCESS. 
 
 HALF-TONE Negatives must be softer, and 
 possess more half-tone than requisite for silver 
 printing. When examined by transmitted light, they 
 should appear clear in the shadows, and not too dense 
 in the half-tones. 
 
 Line Negatives. Negatives for the reproduc- 
 tion of line subjects need not possess the absolute 
 opacity requisite for silver printing, but the lines 
 should be clear glass, entirely free from fog or 
 deposit. 
 
 Stripping the Negative. The fixed and 
 washed negative is flooded over with a solution of 
 gum arabic in water (i to 20), to which has been 
 added a few drops of a solution of chrome alum 
 (i to 60). Allow to dry, retouch with lead pencil, 
 and edge with tallow to prevent overflow, place upon 
 a levelling stand, warm moderately, and coat with a 
 solution of gelatine 100 parts, glycerine 15 parts, 
 alcohol 100 parts, water 400 parts, allow to set, and 
 place against a wall to dry, the coated side out- 
 wards, the plate standing upon clean blotting paper. 
 The operation of drying will probably take a day or 
 two, and when quite complete, it is again coated with 
 collodion, and again dried. After allowing to remain 
 in a damp place for two or three hours, cut around 
 the edges with a knife, and strip off the film, which 
 
128 Collotype and Photo-Lithography. 
 
 may then be printed from either side, and after use 
 may be stored in a book, the leaves of which consist 
 of smooth paper. 
 
 Reproduced Negatives. Coat a plate with a 
 solution of gum arabic 50 parts, dextrine 50 parts> 
 honey 10 parts, sugar 25 parts, glycerine 5 parts, 
 bichromate of ammonium 15 parts, ammonia 50 
 parts, water 1,000 parts. After drying, expose under 
 a negative, dust over with graphite, coat with plain 
 collodion, and wash in clean water until all yellow- 
 ness disappears. 
 
 Substratum. (i.) Water 300 parts, white of 
 egg 300 parts, ammonia 50 parts. (2.) Water 300 
 parts, gelatine 10 parts, bichromate of potassium 10 
 parts. Filter both solutions, and mix, taking care 
 that the temperature never exceeds 32 C. ; pour 
 upon glass plates heated to 30 C., and dry at a 
 temperature of 22 C. After thoroughly cleaning 
 the back of the plate, place, face downwards, upon 
 a black cloth, and expose to light through the glass 
 till the coating becomes brownish. To test if 
 sufficiently exposed, dampen a portion of the film 
 with the finger, scratch with the nail, and the scratch 
 should stand out perfectly sharp. 
 
 The intermediate layer is to ensure the 
 better adhesion to the glass of the print layer proper, 
 and to facilitate the retention of moisture while 
 printing. It consists of gelatine 100 parts, water 
 1,500 to 1, 800 parts, alcohol 150 parts, glycerine 
 5 parts, bichromate of potassium 5 parts. This is 
 spread over the substratum, allowed to dry, and 
 
Collotype and Photo-Lithograpliy. 
 
 exposed to diffused light, or allowed to stand for 
 twenty-four hours, well washed, and allowed to dry 
 spontaneously, after which it may be kept for weeks. 
 
 The Print Layer consists of water 1,500 
 parts, gelatine 100 parts, bichromate of ammonium 
 30 parts, complete solution being effected by means 
 of a water bath ; the drying box heated to 45 to 50* 
 C. Place the levelling stand upon a sheet of white 
 paper, carefully dust and accurately level the glass 
 plate, and coat, using 30 ccm. of solution to cover 
 2 5 x 35 cm - f surface, avoiding any overflow of 
 solution. 
 
 The Washing Water used after printing in 
 the copying frame should not exceed 22 C. in the 
 summer, or fall below 10 to 11 C. in the winter. 
 Washing should be continued until the film is free 
 from colour, and a final rinse should be given under 
 a rose. Allow to dry slowly. 
 
 Etching Solution. Water 500 parts, glycerine 
 500 parts, chloride of sodium 15 parts, or hypo- 
 sulphite of soda 15 parts. 
 
 Rolling Up. If the picture take too much 
 ink, wash off with turpentine, carefully wipe with a 
 cloth, and continue the etching. If it take little, 
 wash off the ink with etching fluid, and place in a 
 hardening solution of chrome alum i part, water 6 
 parts, wash, dry, and once more etch for a quarter 
 of an hour. 
 
 Varnish for Prints Bleached shellac 100 
 parts, dissolved in alcohol 300 parts, adding 
 ammonia 300 parts, further adding, with constant 
 agitation, 600 parts of boiling water. 
 
130 Collotype and Photo-Lithography. 
 
 CHAPTER XVII. 
 
 PRACTICE OF PHOTO-LITHOGRAPHY. 
 
 IN photo-lithographic operations, quite a different 
 set of conditions has to be considered as com- 
 pared with Collotype. An explanation is, of course, 
 not far to seek, as both the chemical and physical 
 properties of the lithographic stone and the exposed 
 chromated gelatine layer are so extremely different. 
 To the better understanding of the operations, the 
 composition of the lithographic stone and the 
 principles underlying the process may be first 
 considered. 
 
 Senefelder is a name inseparably connected 
 with lithography, as it was he who, after a con- 
 tinuous and laborious research, discovered the 
 remarkable properties of the Solenhofen limestone, 
 who thoroughly worked out the conditions under 
 which printing with fatty inks could be carried out, 
 and so thorough and conclusive were whose re- 
 searches that the process as now practised may 
 be said to be actually identical with those of the 
 discoverer. He was by inclination a dramatic 
 author, but failing to find a publisher for the 
 productions of his brain, he conceived the idea of 
 publishing his own works. At a printer's he 
 acquired the necessary knowledge to perform the 
 
Collotype and Photo-Lithography. 131 
 
 work, but lacked the funds to purchase press or 
 type. He then turned his attention to copper- 
 plate, made many unsuccessful attempts with an 
 old one he possessed, and when that was unfit 
 for further experiment, extended his operations to 
 the pewter plates of his mother's dining service, but 
 still without success. 
 
 By accident, his next experiments were made 
 upon a stone procured from Cellheim (Solenhofen), 
 and which up to the present had served him as a 
 slab for his ink. For want of paper and ink to write 
 a domestic account for his mother, he casually used 
 the surface of this stone in lieu of paper, using as an 
 ink a mixture of soap, wax, and soot, with the 
 intention of copying upon paper later on. When 
 about to clean the slab, the thought flashed across 
 his mind why not etch the stone with a dilute solution 
 of nitric acid ? The experiment was tried, and 
 succeeded beyond expectation. Upon this simple 
 accident has been built up the whole process of 
 lithography. It was only in 1799, after a prolonged 
 and severe struggle, that he was granted protection 
 for his art in Bavaria. 
 
 The acid etches away a very thin layer of the 
 unprotected stone, while the writing is not attacked, 
 but left slightly in relief. Senefelder first with a 
 dabber, and later with a piece of wood covered 
 with cloth inked in the writing, and so produced 
 impressions, the earliest of which were sheets of 
 music. The etching of a lithographic stone bearing 
 
132 Collotype and Photo-Lithography. 
 
 a drawing or transfer in lithographic ink has a two- 
 fold action, each of which facilitates the printing. 
 In addition to the slight relief already mentioned, as 
 resulting from the application of the acid, the latter 
 forms upon the surface of the stone, where attacked, 
 nitrate of calcium, which resists and refuses the fatty 
 ink upon the surface of the roller, and if the surface 
 of the stone be kept constantly damp it becomes 
 possible to roll up the drawing, to which alone the 
 ink adheres. 
 
 Lithographic stones do not consist merely of 
 carbonate of lime, but contain also silica, alumina, 
 and some iron ; the colour is a useful indica- 
 tion of quality, those presenting a bluish grey 
 appearance being most highly prized, while those 
 of a yellow colour are somewhat inferior. The stone 
 may be split into various thicknesses, and prepared 
 for use by grinding either one or both surfaces. 
 They are placed face to face, and the first grinding 
 is completed with coarse sand, for the second grind- 
 ing a finer sand is employed between the two surfaces, 
 and this is succeeded by a grinding witii pumice 
 stone and water, the stone being finally polished 
 with snake stone. The so-called lithographic chalk, 
 with which the drawing on stone is sometimes 
 executed, is composed of finest lamp black (merely 
 added for colour), soap, wax, tallow, and shellac; 
 during the etching, these ingredients undergo a 
 change, and form with the stone a chemical compound 
 of great stability. Since the fatty acids of the soap 
 
Collotype and Photo -Lithography. 133 
 
 and tallow namely, oleic and margaric acid set 
 free by the nitric acid, combine in the nascent state 
 with the lime to form oleo-margarate of lime. This 
 adheres tenaciously to the stone, and the whole 
 picture may, by the application of turpentine, to all 
 appearances be completely removed from the 
 stone. If the ink roller be again applied, it will be 
 found that even the finest details remain intact, and 
 will reappear of their original strength, the ink 
 only adhering to the oleo-margarate of lime, and 
 not to the surface of the stone, which owing to 
 the etching is wet with nitrate of calcium. 
 
 This is the theory of lithographic etching and 
 printing, to which it has only to be added that soap 
 and tallow must always be present in the inks or 
 chalks used in drawing to produce the combinations 
 referred to. Wax and shellac are only present as 
 binding material. Transfer ink, as used in photo- 
 lithography, must be slightly thinned, and this is 
 best done by means of turpentine, and, if necessary, 
 the occasional addition of a few drops of olive oil. 
 Should the ink be too stiff, or be allowed to dry too 
 much upon the transfer paper, the transfer will pro- 
 bably be faulty, as the ink will only partially leave 
 the paper. If the ink remains in a soft condition it 
 will be absorbed very readily by the clean dry litho 
 stone (not etched). \/ Owing to the avidity with 
 which all grease is absorbed by the stone, it is neces- 
 sary to keep it perfectly free from all such con- 
 taminations. To keep the stone in a clean condition 
 
134 Collotype and Photo-Lithography. 
 
 while printing it must be etched, kept damp during 
 working, and, on completion or suspension of work, 
 the surface should be coated with a thick solution of 
 gum arabic. Before resuming printing operations, it 
 is of course necessary to remove the gum from the 
 surface of the stone, which is done with a damp 
 sponge. 
 
 As an introduction to the practical work of 
 lithographic transferring and printing the following 
 description of the autographic method will be found 
 of interest, especially as it bears some similarity to 
 the more difficult process of photo-lithography, and 
 enables everyone possessing a lithographic press and 
 stones to print their own circulars, price lists, &c. 
 
Collotype and Photo-Lithography. 135 
 
 CHAPTER XVIII. 
 
 T 
 
 AUTOGRAPHY. 
 
 HERE are several methods of transferring 
 from specially prepared, or even any strong 
 well-sized paper. * As the latter may be most con- 
 venient, proceed as follows : Write with autographic 
 transfer ink, readily procurable from dealers in litho 
 requisites ; this will keep for years, and may be used 
 with any clean steel pen. After the writing has 
 dried, damp the back of the paper with dilute nitric 
 acid i to 3 of water. When the writing is visible 
 through the back of the paper, the sizing has been 
 acted upon sufficiently ; the sheet should be placed 
 in a porcelain dish, washed in several changes of water, 
 and blotted off, leaving it evenly damp without being 
 exactly wet. In the meantime a stone should be 
 adjusted upon the bed of the press, rubbed over with 
 pumice powder, and warmed this may be easily 
 effected by pouring spirits over the stone and 
 igniting it. A suitable scraper one which, when 
 pressed against the stone, allows no light to pass 
 between, and which should not be wider than the 
 stone is adjusted in the scraper box. The screw or 
 other appliance for regulating the pressure is then 
 
 * Transfer paper is more reliable. 
 
136 Collotype and Photo-Lithography. 
 
 adjusted. The transfer is carefully and accurately 
 placed upon the warm dry stone, with the writing or 
 drawing face downwards in contact with the polished 
 .surface, a few sheets of waste paper are placed over 
 the whole, the tympan (the upper surface of which 
 has been freely rubbed with tallow) is lowered into 
 position, the bed is then pushed, with the stone so 
 -covered, under the scraper box, so that the scraper 
 may come down, not upon the extreme edge of the 
 -stone, but about four or five cm. from the end, lower 
 the scraper (or, according to the construction of the 
 press, raise the bed) and pull through under gentle 
 pressure. Release the pressure of the scraper, ^ 
 withdraw the bed, and raising the corners of the 
 waste sheets used as backing paper, convince yourself 
 that the transfer is in a proper position and has not 
 moved ; replace the covering paper, change the posi- 
 tion of the stone so that it passes under the scraper 
 in a reversed position, pass through the press again, 
 this time with greater pressure. Repeat these opera- 
 tions three or four times, on each occasion under 
 steadily increasing pressure ; remove the transfer 
 -carefully by one corner, and allow the stone to 
 become cold ; sponge over with thick gum solution, 
 and in this condition it may be left for any length of 
 time. Great care must be taken that none of the 
 tallow used on the tympan, or other grease, comes in 
 -contact with the stone, either by the hand, covering 
 paper, or other means. 
 
 If the transfer should exhibit any signs of weak- 
 
Collotype and Photo-Lithography. 137 
 
 ness while the stone is still covered with plain gum 
 water, take, upon a small linen pad, a little ink 
 thinned either with tallow or a few drops of tur- 
 pentine ; by careful rubbing in different directions 
 the lines will be considerably strengthened. Plenty 
 of gum must be kept upon the surface of the stone 
 during this operation, at the completion of which it 
 may be removed with a sponge and water, and the 
 inking-up completed with the roller and the stone 
 gummed in. 
 
 Before printing, the gum has to be removed by 
 water, and the stone rolled up with a moderately stiff 
 ink ; it is then etched with gum water rendered 
 slightly acid by a few drops of nitric acid. The best 
 test for the acidity of this solution is to add just so 
 much acid to the gum water that, after its applica- 
 tion to the edge of the stone for two or three seconds, 
 scarcely perceptible bubbles of carbonic acid gas will 
 show. This is applied evenly to the drawing with a 
 sponge, and allowed to act for a few seconds. 
 
 Should the ink " take " to the stone in places 
 other than the design or writing, rub the spot at 
 once with woollen material moistened with gum 
 water ; this will clear away the superfluous ink, but 
 the part should be carefully watched during the 
 printing for any recurrence. After the removal of 
 each impression the stone is damped over the whole 
 surface with a damping cloth before another applica- 
 tion of the inking roller. 
 
 For the production of perfect impressions avoid 
 
138 Collotype and Photo-Lithography. 
 
 contact of the hands with the face of the paper or 
 stone, and care must be exercised that all matters 
 connected with the printing are kept scrupulously 
 clean, any contamination of a fatty or greasy nature 
 especially being strenuously avoided. The paper 
 used in lithographic printing is usually slightly 
 damped by placing between sheets of damp blotting 
 paper ; such proceeding is not absolutely necessary, 
 as dry sized paper may also be used. 
 
 The above detailed description of the necessary 
 sequence of operations in the Autographic transfer 
 process will assist in understanding that of photo- 
 lithographic transfer, which requires still more care, 
 and the use of a special transfer paper so prepared 
 that it is sensitive to light. 
 
 THE BITUMEN METHOD. 
 
 This, the earliest photographic process, was 
 discovered and described by Niepee even before the 
 discovery of photography or silvered plates. It 
 depends on the peculiar property asphalt possesses 
 of losing its solubility in ether, benzine, or turpen- 
 tine after prolonged exposure to light. If it be 
 dissolved in turpentine in a photographically dark 
 room and the solution poured upon a well-polished 
 metal plate or lithographic stone, dried, and exposed 
 under a reversed negative (otherwise the impression 
 yielded in printing will be reversed) for two or three 
 days" in sunlight, the picture may be developed with 
 
 *The bitumen most suitable is that variously known as Syrian asphalt, 
 Jew's pitch and bitumen of Judea. This is finely powdered and placed in a 
 bottle with twice the bulk of ether and occasionally agitated for five hours, 
 
Collotype and Photo-Lithography. 139 
 
 turpentine or benzine, either of which solvents will 
 remove the layer from such portions as have been 
 unexposed to the light and reveal a picture in asphalt 
 that may be rolled or inked-in and capable of with- 
 standing etching. This direct process, as applied to 
 photo-lithography, is now of little practical value 
 owing to the introduction and perfection of the 
 transfer process. It is, however, most valuable in 
 heliographic engraving or etching and for the pro- 
 duction of zinc and copper printing plates. 
 
 DIRECT PHOTO-LITHOGRAPHY. 
 
 This method is little known, and it may be said 
 that it has never been developed to a practical issue. 
 It is here only incidentally referred to, but at the 
 same time the fact may be pointed out that these 
 two direct photo-lithographic processes possess a 
 value, inasmuch as they may be utilised in a com- 
 paratively easy manner for the production of grained 
 or half-toned pictures, presenting less difficulties 
 than by the transfer process. 
 
 On to a well-cleaned stone, the surface of which 
 may be either finely grained or polished, a solution 
 of gum arabic and bichromate is spread, dried in the 
 dark, and exposed for a sufficiently long time under 
 a negative ; if the latter be a film it will facilitate 
 the examination from time to time of the progress of 
 the copying. On completion of the exposure the 
 
 at the end of which time the ether may be poured off and fresh supplies 
 added so long as any portion soluble in the ether remains. The purified 
 residuum maybe dried and dissolved in benzole or chloroform ; this will yield 
 a solution which may be used as above, but poisoning, perhaps, twenty times 
 its sensitiveness. The picture is developed with turpentine. 
 
140 Collotype and Photo-Lithography. 
 
 stone should be well washed with water and rolled 
 in with ink. 
 
 Morvan's process is of a similar nature ; a stone 
 is coated with an admixture of albumen 200 g. r 
 water 300 g., bichromate of potassium 50 g., dried 
 and exposed under a stripped or paper negative. 
 The stone is then first washed with soap, and after- 
 wards distilled water, and then rolled up, gummed, 
 and the ink allowed to set awhile, after which print- 
 ing may be at once commenced. In none of these 
 methods is mention made of etching the stone after 
 inking- in, as is usual in lithography ; it may be here 
 noted that photo transfers will not withstand so 
 vigorous an etching as drawings executed upon stone 
 in the usual manner. A photo-lithographic transfer 
 may be quite ruined, even entirely destroyed, by 
 careless etching ; this is therefore a point of great 
 moment, and one which has not usually been con- 
 sidered or dealt with in published methods of pro- 
 cedure. We shall have occasion to again refer to it, 
 
 PHOTO TRANSFER FROM PAPER. 
 
 In this method, now universally employed,, 
 success may be said to depend more particularly 
 upon two points, (i.) The paper for the transfer. 
 (2.) The suitability of the negative for the purpose in 
 view. The properties and preparation of a suitable 
 transfer paper demand a few words. It should be 
 of substantial body, smooth and well sized ; that 
 known as bank post is usually employed in this 
 country. Professor Husnik in his patented process 
 
Collotype and Photo-Lithography. 
 
 proceeds as follows : I part of finest gela 
 swelled, and then dissolved in 24 parts of 
 solution of chrome alum i 100 in water is 
 and the solution while still warm is poured into a large 
 zinc dish heated to 34 R. by means of a petroleum 
 or spirit lamp. Remove any scum from the surface 
 of the solution, float the paper one sheet at a time, 
 and suspend to dry. The sheet is floated upon the 
 gelatine solution a second time, and once more 
 suspended, this time by the diagonal corner to that 
 by which it was previously hung. Prepare a solution 
 of white of egg i part, water 2 parts, and on this 
 float the paper on one side. After again drying 
 it is ready for sensitising, for which operation 
 prepare a bath of water 14 parts, bichromate of 
 potassium i part, methylated spirits 4 parts, 
 adding sufficient ammonia to turn the reddish 
 solution a bright yellow. If the paper is not pre- 
 pared in large quantities, but only for immediate use, 
 the ordinary gelatine paper of commerce* may be 
 employed with advantage, if further prepared by 
 floating upon a bath of albumen (beaten to a froth 
 and allowed to stand) 50 parts, water 50 parts, 
 bichromate of potassium or ammonium 7 parts 
 (Markl), upon which bath the paper should be floated 
 for five minutes. This solution is subject to the 
 disadvantage that even in the dark it will not keep 
 for more than a day or two, therefore it must be 
 
 * For instance, the double transfer paper as used in the carbon process. 
 TRANS. 
 
142 Collotype and Photo-Lithographv. 
 
 used at once. All photo-lithographic transfer papers, 
 after sensitising, should be used within a few hours of 
 their preparation or their good qualities are partially 
 sacrificed, the solubility of the albumen layer in cold 
 water being impaired. Photo-lithographic transfer 
 paper prepared as above described has been for some 
 time in the market, and may be procured as an 
 article of commerce, in an unsensitised condition; it 
 will keep indefinitely in this state, and may be 
 sensitised as required. The surface should not be 
 allowed to remain in contact with the bath, neither 
 should the immersion be lengthy, as in either case 
 the surface of the paper would probably suffer. 
 After drying by suspending by one corner in the 
 dark, the chromated paper is exposed under a 
 suitable negative if possible to the sun for a few 
 minutes only ; it may be examined by non-actinic 
 light, and when the image appears brown or grey 
 upon a yellow ground, and all details are visible, it is 
 removed from the copying frame and entirely covered 
 with a thin coating of transfer ink. This as pur- 
 chased is much too stiff for use, and must be reduced 
 by means of turpentine to such a consistency that it 
 is possible to distribute an even and quite thin 
 layer upon the surface of the print, without its 
 penetrating to the paper. The ink should be so 
 thin that it presents a grey, not black, appearance. 
 
 Those who may find it necessary, or who care to 
 prepare their own ink, should take chalk ink 
 (printing) 4 parts, beeswax 10 parts, resin 7 parts, 
 
Collotype and Photo-Lithography. 143 
 
 turpentine 40 parts, tallow 8 parts, Prussian blue 6 
 parts, ground and mixed in a paste. The chalk 
 printing ink should be melted by gentle heat, then 
 add the wax and resin in a molten condition, then 
 the tallow, and lastly the Prussian blue and turpen- 
 tine ; on account of the inflammable nature of the 
 latter these operations should not be conducted at 
 an open fire. If, after prolonged keeping, this ink 
 becomes tough, and does not readily leave the 
 transfer paper when transferring to stone, the addi- 
 tion of a few drops of olive oil will restore it to a 
 usable condition. The ink is best applied by 
 means of a fine, dry sponge, * with which it should 
 be spread on the transfer as evenly as possible, 
 during which operation the print must be protected 
 from actinic light ; on its completion the print is 
 placed aside to allow the turpentine to evaporate. 
 This in a warm room will be about ten to fifteen 
 minutes ; the print is then placed in cold water, care 
 being taken to remove any air-bubbles from its 
 surface. After remaining for about half an hour the 
 uppermost layer will have become sufficiently loose 
 to allow of its removal, together with the adherent 
 ink not forming part of the picture, upon the appli- 
 cation of slight friction. 
 
 The Development is readily effected by means 
 of a small, fine wet sponge, or a pad of cotton wool 
 well moistened, which is passed over the print a few 
 times with gentle pressure ; it will be found con- 
 
 *A smooth composition roller answers equally well. TRANS. 
 
144 Collotype and Photo-Lithography. 
 
 venient during these operations to place the transfer 
 face upwards upon a sheet of glass. 
 
 Judgment may be formed at this stage as to the 
 suitability of the negative, and also as to the cor- 
 rectness or otherwise of the exposure under it of the 
 sensitised paper ; if it should have been too short 
 the finest lines will not be firm, but appear broken 
 or "rotten," as it is technically termed. On the 
 contrary, should the exposure have been too long, the 
 spaces between the lines, which should be quite free 
 from ink, will retain a certain amount, in attempting 
 to remove which the transfer will be damaged. 
 
 Washing. Exposure, inking, and development 
 being satisfactory, the print is thoroughly washed to 
 remove the chrome salt. Dry the transfer by means 
 of repeated applications of blotting-paper, and it is 
 then ready for transferring. 
 
 Transferring. The print should retain a little 
 moisture, but be by no means wet. It should adhere 
 to the warmed stone to prevent any probability of it 
 moving while passing through the press. 
 
 Transfer too Adhesive. Should the gelatine 
 surface, in the judgment of the operator, appear 
 likely to prove too adhesive, it may be further dried 
 before use, or placed for two minutes in a one per 
 cent, solution of tannin, and again dried between 
 blotting-paper. 
 
 Preparation of Gelatine Transfer Paper, 
 as used in the Imperial Military Geographical 
 Institute in Vienna, is described as follows in the 
 
Collotype and Photo-Lithography. 145 
 
 " Photographic Correspondence" : A sheet of well- 
 sized paper is soaked in a dish of water, and when 
 thoroughly limp is allowed to drain, and then placed 
 on a horizontal glass plate. All air bubbles and 
 superfluous moisture are removed by blotting-paper 
 and a squeegee, the edges of the paper are turned up 
 to the depth of about 2 cm., and a warm gelatine 
 solution (i to 30) poured upon the paper. It sets in 
 a few minutes, and the sheets are placed upon wire 
 gauze to dry, this operation usually occupying about 
 two days. A day before using the gelatine paper is 
 sensitised by immersing for three minutes in a cold 
 bath of bichromate of potassium (i to 15). On 
 removal from the bath it is allowed to drain> and the 
 gelatine side placed upon a glass plate. The back 
 is dried with blotting-paper, and all air bubbles 
 removed. These operations and the subsequent 
 drying must be performed in a non-actinic light. 
 It may occur that after these operations the sheets 
 when dry adhere partially or wholly to the glass 
 plate. To prevent such an occurrence it is well to 
 wax the plate, as in the carbon process, or to apply 
 to the surface a weak solution of ox-gall.* When 
 dry the sheets are cut to the required size and printed 
 under the negative. On removal from the printing 
 frame they are placed in cold water until quite limp, 
 removed, placed face upwards upon a glass plate, 
 and surface dried with blotting-paper. Should the 
 
 * A more reliable method of imparting to the surface of the paper a high 
 gloss is to squeegee it down upon a ferrotype plate, the surface of which 
 requires no preparation, and the risk of sticking is nil. TRANS. 
 
146 Collotype and Photo-Lithography. 
 
 gelatine swell too much the sheet is placed for two 
 
 minutes in a chrome-alum solution (i to 200) and 
 again blotted. Ordinary transfer ink, thinned with 
 
 turpentine, is now thoroughly rolled up on the inking 
 slab by means of a leather roller (as previously 
 described in the instructions under Collotype) ; a 
 fine velvet roller, lightly charged with ink, is then 
 passed over the still moist transfer. Should the 
 latter become dry in places it is again passed through 
 the water bath, and the inking is again proceeded 
 with. If the ink adhere to other parts than the 
 design it is easily removed by the application of a 
 damp sponge or the tip of the finger. The process 
 of transferring to stone is as previously described. 
 The stone itself is prepared in the manner described 
 for the autographic process (see page 135). Damp 
 the back of the transfer with water only, and after 
 passing through the press several times, remove the 
 paper from the stone ; if of good quality this may 
 be done without tearing. The transferred impres-' 
 sion being still easily obliterated, it is better to let the 
 stone stand for a few hours without gumming ; this 
 will allow the ink to dry deeper into it. Coat the 
 whole of the surface with a moderately thick solution 
 of gum, and again allow to dry. In this condition it 
 may remain indefinitely, but under any circumstances 
 it is advisable to allow it to remain a day before 
 etching and printing. The gum solution used should 
 be freshly prepared, as when old it becomes acid and 
 acts as a mild etching medium. Remove the gum 
 
Collotype and Photo-Lithography. 147 
 
 with a clean sponge previously to printing, and while 
 the stone is evenly clamp with gum solution the 
 picture may be either rolled up with stiff chalk ink, 
 applied by means of a leather roller, or, as preferred 
 by many, rubbed in with a sponge containing 
 thinned transfer ink. When the drawing appears 
 clean and perfect the stone is washed with a wet 
 sponge, coated with gum, placed aside to dry, and 
 allowed to stand for a day. After the removal of 
 the gum proceed as previously described, viz., roll 
 up with stiffish ink, nowhere allowing the stone to 
 become dry, and etch. This operation must be con- 
 ducted with care and judgment, or there will be a 
 probability of losing the finer lines of the drawing. 
 The best mordant to use is nitric acid, so dilute as to 
 taste no stronger than lemon juice, and which, placed 
 upon the edge of the stone for a few seconds, will 
 show only slight effervescence. To this is added a 
 little gum-water, and it is then evenly and quickly 
 spread over the stone. After being allowed to act a 
 few seconds, the stone is sponged over with clean 
 water, and is then ready for printing from." There 
 are many practical lithographers who prefer to 
 entirely remove the visible image from the stone by 
 means of turpentine before printing. A little gum is 
 left upon the stone, and while the latter is still moist 
 
 * For etching extremely delicate transfers a decoction of Aleppo gall with 
 gum is to be recommended. 15 gr. of crushed nut galls are boiled for one 
 hour in half a kilo of water and strained through a cloth. To etch the trans- 
 fer add a few drops of this solution to a solution of gum of a syrupy 
 consistency ; spread over the stone with a soft sponge, and allow to dry. 
 
148 Collotype and Photo-Lithography. 
 
 the drawing is removed by means of turpentine upon 
 a piece of rag ; the latter must not be too frequently 
 changed, or a too liberal supply of turpentine made 
 use of, or the drawing may be irreparably damaged. 
 Unless the latter be the case the picture will reappear 
 upon applying the roller charged with chalk ink. As 
 may be expected, the first few impressions are 
 seldom so perfect as the later productions. After 
 each impression is removed the stone is at once 
 slightly moistened. For this purpose a soft, clean 
 sponge is suitable, or damping cloth, as supplied by 
 dealers in printing materials. The sponge or cloth 
 should be thoroughly wetted, wrung as dry as 
 possible, and in that condition will possess the neces- 
 sary dampness. In rolling it should be borne in 
 mind that as in Collotype a stronger grip of the roller 
 handles and heavy pressure with slow rolling will 
 deposit ink upon the drawing while, on the other 
 hand, light quick rolling of the drawing will tend 
 to remove the ink. To leave the stone without 
 gumming after transferring is a convenient method 
 of rendering the transfer more receptive of the 
 ink. In lithographic as compared with Collotype 
 printing the ink is reduced to a far greater extent 
 with varnish, while both the inking slab and roller 
 are charged far more heavily. The paper may be 
 damp, or a dry, w 7 ell-sized paper may be used. 
 
Collotype and Photo-Lithography. 149 
 
 CHAPTER XIX. 
 
 NEGATIVES FOR PHOTO-LITHOGRAPHY. 
 
 AN unconditionally good negative is required for 
 photo-lithography, and those who have not 
 seen one produced for the purpose by an expert 
 should endeavour as a first step to do so, or they 
 will scarcely be likely to devote the attention neces- 
 sary for producing one of a thoroughly suitable 
 character. Not only must the lines of the copy be 
 represented in the negative by clear glass, and the 
 white ground of the original be represented by 
 opacity, but the utmost sharpness of definition of 
 the finest dots and lines to the very corners of 
 the plate is absolutely necessary to render the 
 negative thoroughly serviceable. To produce such 
 a negative a lens entirely free from distortion, and 
 capable of giving microscopic definition, is, of course^ 
 a first necessity.* 
 
 The Wet Collodion Process is better adapted 
 than any other for the production of suitable nega- 
 tives, possessing the necessary density and freedom 
 from fog or veil. The bath must work with the 
 utmost cleanliness, and the collodion should not be 
 used too soon after iodising. The developer works 
 
 ' Lenses of the rectilinear or symmetrical class are best. 
 
150 Collotype and Photo-Lithography. 
 
 better when not quite fresh, and should contain a 
 .sufficiency of acid, and the negative, after fixing, 
 should be subjected to a vigorous intensification. 
 
 Professor Husnik thus comments upon negatives 
 for photo-lithography : 
 
 " As in photo-lithography only subjects in black 
 and white line or stipple can be reproduced, to the 
 entire exclusion of half-tone, the negatives should 
 represent the copy by clear lines and opaque spaces. 
 This is seldom the case except in instances where the 
 drawings are specially prepared, and the subjects 
 somewhat bold and coarse. For example, in copy- 
 ing a proof from a fine steel engraving the graduated, 
 grey, hair-lines, appear in the negative somewhat 
 veiled, whereas the intermediate spaces between 
 close shading, and which are somewhat toned in 
 the print, are not developed actually opaque in the 
 negative. On this account the fine hair-lines will 
 take longer to print in the copying-frame than the 
 bolder shadow lines. The latter may develop fault- 
 lessly, while the ink may leave the hair-lines. 
 The intermediate spaces between close shading may 
 not be sufficiently opaque in the negative, conse- 
 quently the print is over-exposed in these portions, 
 and during development remains covered with ink. 
 Such faults must be overcome as far as possible by 
 shading the negative during printing in the usual 
 well-known manner." 
 
 The Colour and condition of the original copy 
 will greatly influence the class of negative it is 
 
Collotype and Photo-Lithography. 151 
 
 possible to obtain, and if allowable it will be 
 advisable 
 
 To Bleach old engravings or other copies, 
 either yellow from age or stained, by immersing 
 them in eau-de-javelle* 10 cc., water 100 cc., wash in 
 water for two hours, and finally in a weak solution 
 of hyposulphite of soda. 
 
 Intensifying. Having developed a clear, sharp 
 negative, wanting only in density, it must be intensi- 
 fied to the utmost limit without fogging first with 
 citric acid, pyrogallic acid, and silver. This solution 
 may be applied either before or after fixing, prefer- 
 ably the former ; if this course is adopted, after 
 washing and fixing, and again thoroughly washing, 
 the final intensifying operations may be proceeded 
 with. Opinions vary as to the actual best method 
 to adopt, but preference is usually given to an 
 intensification by a salt of mercury or lead ; under 
 any circumstances there must be a good deposit of 
 silver to work upon, or the necessary density cannot 
 be obtained. In fact, a negative too thin, submitted 
 to mercurial combinations, particularly the bichloride, 
 will become more bleached and spotty, and the 
 after application of sulphide of potassium will not 
 again restore it ; the deposit will assume a dark 
 brown appearance, but the spots arising from the 
 mercurial salts will still be apparent. The two 
 
 1 Chloride of lime.. .. i oz. Water 1502. 
 
 Carbonate of potash .. 2 Water 5 
 
 Mix the two solutions together, boil, and filter before use. 
 
152 Collotype and Photo-Lithography. 
 
 mercurial salts referred to are (i) Bichloride of 
 mercury, corrosive sublimate, a well-known and 
 highly-poisonous substance used in solution in water, 
 and (2) iodide of mercury, which, used in intensifica- 
 tion, acts more evenly, though with somewhat less 
 energy. This substance, which is of a beautiful red 
 colour, is insoluble in water, but is soluble in sub- 
 limate, and also in a solution of iodide of potassium. 
 It is recommended for intensification, and is easily 
 obtained by dropping into a solution of bichloride of 
 mercury with agitation a concentrated solution of 
 iodide of potassium until the red precipitate as first 
 formed is again dissolved. This yellow solution may 
 be diluted as required by an addition of ten times 
 its volume of water. If, instead of flowing the 
 solution over the negative, a dipping bath be used, 
 into which the negative is steadily lowered for a few 
 seconds, a more uniform intensification is likely to 
 ensue. Carefully watch the plate, and stop the 
 action before it goes too far, or the silver deposit will 
 lose strength in parts. An important gain in density 
 may be obtained by exposing to sun or daylight a 
 negative which has been developed and intensified 
 with pyrogallic acid, fixation taking place after drying. 
 The negative must be thoroughly washed before 
 exposure to light, and with ordinary care there is 
 little danger of fogging. 
 
 Illumination of the Copy should be perfectly 
 even, a front light being made use of, and direct 
 sunlight if possible. The latter is seldom admitted 
 
Collotype and Photo-Lithography. 153 
 
 direct into the studio, and against outside work wind 
 and rain are almost fatal objections. Where much 
 copying has to be done it will be found an advantage, 
 if at certain hours of the day the sun shines direct 
 upon the studio, to remove all blinds, screens, or 
 other obstructions, and so allow the rays to fall direct 
 upon the print or drawing to be copied. 
 
 A Side Light, particularly if direct sunlight, 
 must be avoided, as any unevenness or grain of the 
 paper will be exaggerated and rendered more apparent 
 if lighted in such a manner. 
 
 Under Exposure, if slight, is a fault much to 
 be preferred to an error in the opposite direction. 
 
 New Transfer Paper for Photo-lithography. 
 In the photographic office, Calcutta, a new method 
 of preparing the photo-lithographic transfer paper 
 with arrowroot has quite recently been introduced, 
 which, as is said, has the advantage of being much 
 cheaper than the method of coating with gelatine 
 usually adopted, and of giving results quite as good, 
 if not even better, than by the old proofs. Bank 
 post paper is coated in the usual way with two coats 
 of the following mixture : 
 
 Arrowroot 140 parts 
 
 Bichromate of potash ... ... 70 ,, 
 
 Water ... ... 3,500 
 
 After exposure to light, the prints are coated with 
 transfer ink in the press as usual, the transfer ink 
 used being composed of 
 
 Hard re-transfer ink (plate to 
 stone) ... ... ... ... 100 parts 
 
 Lithographic chalk ink ... ... 100 ,, 
 
 Palm oil 7 L 
 
154 Collotype and Photo-Lithography. 
 
 After inking in the prints are washed off with hot 
 water, hotter than is required for gelatine transfers. 
 The arrowroot transfer prints are found to go down 
 well on the zinc without sticking, and give clear, 
 sharp transfers. 
 
 Gelatine Plates have hitherto been considered 
 almost useless for photo-lithography. Messrs. 
 Mawson and Swan, however, have recently intro- 
 duced a special make, known as the " Photo- 
 mechanical " plate, which gives negatives of great 
 density, and at the same time clearness in the 
 shadows. The makers recommend the ammonia- 
 pyro developer, with meta-bisulphite of potash. It 
 will be found of considerable advantage if, before 
 proceeding with the development, the plate be sub- 
 mitted for one minute to a bath of water 2 ounces, 
 gallic acid 6 grains ; this, without prolonging the 
 development, will add considerably to the density of 
 the resulting negative. 
 
Collotype and Photo* Lithography. 155 
 
 CHAPTER XX. 
 
 APPLICATION OF THE CARBON PROCESS TO PHOTO- 
 LITHOGRAPHY. 
 
 AN Ingenious Process, capable of yielding 
 satisfactory results, is one in which a carbon 
 print is transferred to and developed upon the stone 
 direct. Such operation will present no difficulty to 
 those familiar with the details of the process. In the 
 " Photographic Archives," vol. 17, page 193, are to 
 be found working details, and it is there shown that 
 by this method it is possible to directly transfer to 
 stone pen and ink sketches, impressions from wood- 
 cuts, or copper-plates, without the necessity of a 
 photographic negative. This process may, therefore, 
 be available in cases where anastatic * printing is 
 not applicable. 
 
 To those unacquainted with carbon printing 
 it may be pointed out that it is a most valuable pro- 
 cess, affording great facilities for the reproduction 
 and reversal of negatives for Collotype. A knowledge 
 
 * The anastatic process consists in reproducing by zincography a copy 
 of any recently printed matter. The subject for reproduction is moistened 
 on the back with dilute nitric acid. It is then laid face downwards upon a 
 freshly polished sheet of zinc and passed through the press. Printing is 
 then proceeded with as in zincography. A lithographic stone may also be 
 used, if, before laying down the impression, the face is moistened with turpen- 
 tine, and allowed nearly to dry. 
 
156 Collotype and Photo-Lithography. 
 
 of the process is here presumed, as it would necessi- 
 tate too wide a digression to give an ample idea of 
 the many useful applications of this beautiful and 
 permanent method of printing. Very complete 
 instructions will be found in Dr. Leisegang's 
 " Carbon Process." As regards the application of 
 this process to lithography, only pictures devoid of 
 half-tone, such as drawings in line and dot or impres- 
 sions from engravings, are suitable for reproduction 
 by this method, if upon clean paper (not too thick) 
 and printed en cne side only. The sensitised tissue 
 may be printed frcm the original by contact, in the 
 printing frame, instead of producing a negative in 
 the camera by contact upon a dry plate. Should it 
 be decided to print direct from the copy surround the 
 edges of the same with strips of black paper or tin- 
 foil, half-an-inch wide, and in a weakly actinic light. 
 So adjust the ordinary sensitised carbon tissue that 
 its edges are about in the centre of the surrounding 
 strips, care being taken that the edges of the tissue 
 nowhere extend beyond them. 
 
 Expose to Daylight for a time, gauging the 
 exposure by means of the actinometer. Probably it 
 will be necessary to print till the 7 shows. 
 
 A Finely -polished Stone is dusted and 
 adjusted in a horizontal position, and flowed over 
 with cold water. 
 
 * Translated by R. B. Marston, and published by Sampson, Low and Co., 
 Fleet Street, E.G. The "ABC of Pigment Printing," published by the 
 Autotype Co., Oxford Street, W.C., may also be recommended. 
 
Collotype and Photo-Lithography. 157 
 
 The Exposed Tissue is placed in cold water, 
 and allowed to soak till quite limp. It is then placed 
 face downwards upon the wet stone, covered with 
 indiarubber sheeting, and squeegeed into close con- 
 tact with the stone ; allow to remain under pressure 
 for half-an-hour to an hour. 
 
 Development is effected by pouring warm 
 water about 100 F. over the back of the exposed 
 tissue. So soon as the colour exudes around the 
 edges of the paper backing, the latter may be 
 removed, and the development proceeded with by 
 continuing to pour warm water over the surface. 
 Only a slight impression should remain the lines 
 showing the bare stone perfectly clear and clean. 
 Allow the stone to dry in a cool, shady place without 
 the application of artificial heat. 
 
 Roll Up with lithographic chalk ink until the 
 surface presents a solid black appearance, stand the 
 stone aside for a few hours to allow the ink to 
 penetrate its surface, and then 
 
 Remove the Negative carbon print from the 
 stone by means of a piece of woollen cloth moistened 
 with a thin solution of gum. This takes some time, 
 but it will be found that the fatty ink has penetrated 
 where unprotected by the carbon negative, and has 
 formed a complete positive. 
 
 Gum In, etch, and proceed as in ordinary litho- 
 graphic operations. It cannot be expected that the 
 operation, as conducted above, will produce the finest 
 results ; the drawing will usually require a certain 
 
158 Collotype and Photo-Lithography. 
 
 amount of retouching at the hands of the litho- 
 graphic artist, who will, however, often be saved a 
 vast amount of trouble. It is obvious that if the 
 proceedings, as described, be carried out, using, 
 however, a photographic glass positive in place of the 
 printed impression, the process will be found capable 
 of giving much finer results, and the exposure will be 
 very materially decreased. 
 
 TRANSPOSING BLACK AND WKITE. 
 
 A modification of the foregoing prccess may be 
 utilised for the reversal or transposition of black to 
 white, or vice vena, of any subject of which a print 
 may be obtained in printing ink. 
 
 An Impression is first obtained either upon 
 sensitised carbon tissue or, preferably, on a thinner 
 paper, coated and sensitised as for photo-lithography. 
 Such paper must not be submitted to a light of 
 much actinic power during or before printing, and 
 as much ink as possible should be used without risk 
 of filling up the work. 
 
 Dust Over the impression while still wet any 
 dense opaque colour, applied by means of wool or 
 camel-hair brush, carefully going over every part 
 and piling on as much colour as possible, after which 
 
 Expose the Paper bearing the print so treated 
 to the light for a short period, dependent upon the 
 light and sensitiveness of the paper. If it be a full 
 impression, well dusted, the latitude in exposure will 
 be very considerable. 
 
Collotype and Photo-Lithography . 159 
 
 Ink Up the whole surface of the paper with 
 lithographic transfer ink, thinned with turpentine, 
 and applied by means of a sponge or roller. 
 
 Develop, as in photo-lithography, either by 
 means of warm or cold water, according to the 
 coating upon the transfer-paper. The sensitised 
 paper, where protected by the ink impression, has 
 not been hardened by the action of the light, and 
 readily parts with the ink and colouring matter. If 
 the impression has been one from ordinary type it 
 will now show in the form of white letters on a black 
 ground. 
 
 Transfer to Stone, and otherwise treat as an 
 ordinary photo-lithographic transfer. 
 
 ENGRAVED NEGATIVES FOR PHOTO-LITHOGRAPHY. 
 
 In certain processes for the production of 
 photo-relief blocks many operators prefer artificial 
 negatives, in the production of which photography 
 has played no part, but which are, on the contrary, 
 the direct production of the artist's hand. 
 
 Factitious Negatives may be produced by 
 coating a plate with a transparent but non-actinic 
 coating, and by removing or erasing in a suitable 
 manner designs may be copied without the use of a 
 camera or lens. Professor Husnik and others have 
 published different methods whereby the artist is 
 enabled to transfer the creations of his pencil to zinc 
 or stone, without resorting to the aid of the photo- 
 graphic negative process, although the subsequent 
 
160 Collotype and Photo-Lithography. 
 
 operations may still entitle it to be styled photo- 
 lithography. 
 
 The process most likely to lead to success con- 
 sists of first coating a glass plate with a strongly 
 iodised collodion, sensitising as usual, well washing 
 on both sides and drying. To engrave, lay the plate 
 upon a black cloth, and the design may be traced 
 and engraved upon the surface by means of etching 
 points or needles. Remove all loose particles of 
 collodion from the plate by gentle brushing when the 
 drawing is completed. Immerse the plate a second 
 time in the silver bath, and develop with either pyro- 
 gallic acid or sulphate of iron developer. 
 
 Husnik proposes to first coat the plate with a 
 solution of pure fuchsin, and afterwards with one of 
 gum, and then engrave as previously indicated.* 
 
 By either of these methods negatives of extreme 
 density and absolute clearness in the lines may be 
 produced and used for obtaining impressions in ink, 
 the transfer of which to stone presents no difficulty. 
 
 It remains to be added that there are several 
 methods of producing grained negatives for photo- 
 
 * Major Waterhouse has published the following ingenious method of trans- 
 forming a drawing on paper into a photographic negative: " A tracing, or 
 drawing, is made in lithographic ink on tracing paper, using plenty of ink 
 on the lines. The drawing is then placed on a board over a piece of blotting- 
 paper, and brushed all over with a strong solution of aniline brown in water ; 
 when dry it is rubbed over with a tuft of cotton wool soaked in turpentine, 
 which removes the ink without altering the coloured ground. The lines then 
 appear clear on a dark reddish brown ground. The negatives thus obtained 
 are good, but more suited for coarse than fine work." It may be suggested, 
 why not transfer the drawing direct to stone, and produce the necessary 
 copies by lithography ? TRANS. 
 
Collotype and Photo-Lithography. 161 
 
 lithography in half-tone, and therefrom a transfer 
 for stone, and so obtaining impressions at a much 
 greater rate than is possible from a Collotype plate. 
 They may each .produce results with a certain 
 amount of success ; but even those from the best 
 methods indicated cannot be compared with Collo- 
 type. The too obtrusive grain of the half-tone 
 pictures so produced destroys much of the finer 
 details, and it is to be regretted that all such 
 processes leave so much to be desired. 
 
APPENDIX. 
 
 THE STEAM COLLOTYPE MACHINE. 
 
 THE earliest steam machines for Collotype 
 printing were made by Faber & Co., of 
 Offenbach ; they were, however, so complicated and 
 delicate in construction that other machines have 
 entirely supplanted them. The three principal 
 varieties are those of Alauzet & Co., of Paris; Koch, 
 of Leipzig ; and Schmiers, Werner & Stein, each of 
 which may be considered entirely successful ; they 
 possess features of great similarity, differing not in 
 principle, but only in details of construction. Con- 
 trasting the work of the machine with that of the 
 press, the printing is much more rapid, and the 
 prints more uniform and regular, while the " life" of 
 the plate is greatly lengthened ; one capable of 
 yielding 250 impressions on the scraper press would, 
 in all probability, give 1,000 on the machine a fact 
 easily accounted for when it is considered that the 
 one is produced by a scraping pressure while the 
 other is made by the rotation of a cylinder. As will 
 be seen by the illustrations, the machines bear a 
 considerable resemblance to those used in litho- 
 graphy they may, in fact, be used for lithographic 
 
164 Collotype and Photo-Lithography. 
 
 printing with very greatly increased inking power. 
 The machines are so constructed that the plate may 
 be inked once, twice, or three times, each inking 
 giving more vigour, but, of course, a corresponding 
 decrease in the number of impressions yielded ; the 
 output may be relatively estimated at 1,500, i ,000, and 
 800 per day. It is, of course, an impossibility to teach 
 machine printing by means of instructions such as 
 may be conveyed in a work like the present, and the 
 following remarks are added more with a view of 
 giving a general idea of the nature of the necessary 
 operations than with any idea of making the reader 
 a competent machine minder. 
 
 The Preparation of the Plate for the machine 
 is identical with its preparation for the hand-press, 
 but greater uniformity, both in the negative, ex- 
 posure, and etching, are demanded than by the 
 hand-press. For the latter considerable latitude is 
 permissible, as the intelligent printer may, by varying 
 his rollers, his rate of rolling and other little dodges, 
 produce perfect impressions from plates which 
 would, under the entirely mechanical action of the 
 machine, fail lamentably. 
 
 Adjustment of the Rollers is so effected that 
 they are lifted about 2 mm. when passing over the 
 inking slabs and the printing plate ; if a greater 
 lift is necessary to bring them upon the printing 
 surface marks will be produced upon the plate, and 
 if arranged for a less lift they will probably skid over 
 the plate, damaging the printing surface. They 
 
Collotype and Photo-Lithography. 165 
 
 should also be adjusted perfectly parallel with the 
 surface of the inking tables, or one side only may 
 come in contact with the work. 
 
 Fixing the Plate to the bed of the machine is 
 effected in several ways, but usually with small clips, 
 as described for the hand-press. All adhering gela- 
 tine, etc., must be removed from the plate, and a 
 thin sheet of white paper inserted between it and 
 the bed of the press. The faces of the metal clips 
 must be protected with strips of leather, cork, or 
 somej such elastic bodies, otherwise the pressure 
 exerted would cause the glass to fly. A straight 
 edge is placed across the machine, and the bed 
 lowered by means of inclined planes attached to 
 suitable gearing until the surface of the plate is well 
 below the circumference of the cylinder, and from this 
 position it is brought up to its proper level, raising 
 each side equally, that the pressure may be perfectly 
 uniform. 
 
 Packing the Cylinder. The cylinders are so 
 constructed that the iron surface does not come in 
 actual contact with the printing paper. In fact, there 
 is a deficiency between the actual and necessary 
 diameter of the cylinder of a few mm., sometimes as 
 much as 7 mm. This is compensated for by the 
 addition to its surface of " packing," which gives 
 a more elastic pressure than the unyielding surface of 
 iron. This packing is not applied to the entire 
 surface of the cylinder, but is so devised that it exerts 
 pressure upon the surface of the picture only. A 
 
1 66 Collotype and Photo-Lithography. 
 
 sheet of smooth four-ply cardboard is attached to the 
 cylinder by means of thin glue, this first sheet usually 
 exceeding the size of the picture. To this is 
 attached a second piece, cut of the exact size of the 
 image, and attached by means of the glue, forming a 
 raised block in exact register with the position of the 
 picture on the printing plate ; this is covered with a 
 thickness or two of fine blotting-paper, and over the 
 whole the sheeting of the cylinder is tightly stretched 
 in the usual well-known manner. It is self-evident 
 that the circumference of the cylinder must traverse 
 at exactly the same speed as the bed of the machine, 
 or there will be a horizontal rubbing or friction 
 between the surface of the printing paper and that of 
 the printing layer, which will result in impressions 
 lacking in sharpness, and ultimate destruction of the 
 plate. 
 
 Masking the Prints for the production of 
 white margins is usually performed by one of two 
 methods, each having advantages and disadvantages 
 which should be carefully considered before adopting 
 either ; both are in practical use. In one is used a 
 light rectangular iron framework or " frisket," con- 
 forming to the size of the cylinder, to which it is 
 attached by hinges. This framework is opened and 
 closed automatically, remaining open during the 
 period the cylinder is resting and the inking is taking 
 place. At this point the "layer-on" inserts the 
 paper, it is seized by the grippers, and the masking 
 frame closes down into suitable grooves in the cir- 
 
Collotype and Photo-Lithography. 
 
 cumference of the cylinder, such grooves 
 useful to prevent any lateral movement of the frame. \ 
 To the latter are attached four movable strips of 
 thin zinc, which may be adjusted by means of set 
 screws to form an opening of any desired size. The 
 printing paper being inserted in the grippers, the 
 frame closes, holding the paper upon the cylinder, 
 the strips of zinc at the same time protecting the 
 edges of the paper from immediate contact with the 
 printing layer, the cylinder revolves, and the printing 
 is effected. In large sizes the zinc strips are neces- 
 sarily of such strength that the edges would cut and 
 damage the printing layer ; it is therefore usual to 
 adjust the strips to within about 5 mm. of the edges 
 of the picture, and by attaching strips of varnished 
 tissue paper to the zinc, reducing the aperture to the 
 size of the picture in hand. In large sizes where 
 thin paper is used, or where narrow margins are 
 desired this system of masking is best, as the whole 
 of the operation is entirely automatic. The layer-on 
 may devote the whole of his attention to removing 
 impressions and inserting fresh paper. 
 
 Another System of masking frequently made 
 use of is one in which an aperture of suitable size 
 is cut in a piece of cardboard, such aperture being, 
 say, 2 mm. larger than the print. The portion 
 removed is reduced in size by 2 mm. all round, 
 leaving it exactly the size of the impression desired. 
 This piece is utilised for packing by attaching to 
 the cylinder as previously described. The cardboard 
 
168 Collotype and Photo-Lithography. 
 
 mask, presenting the exact appearance of a sunk 
 mount, is affixed by means of a bar to the cylinder, 
 and when folded down upon the latter, the " cut 
 out " used as packing exactly occupies the centre of 
 the mask, leaving a marginal space all round of 2 
 mm. Before printing, the mask must be varnished 
 with negative varnish, bitumen in benzol, or other- 
 wise waterproofed, to prevent adhesion to the print 
 layer. The mask has to be turned back by hand at 
 the insertion of each sheet a considerable dis- 
 advantage when compared with the automatic frame. 
 On the other hand, its advantages are simplicity of 
 preparation, and the possibility it allows of masking 
 and printing several irregularly-disposed pictures on 
 one sheet. 
 
 Damping the Plate. The use of the cylinder 
 pressure has further advantages than merely pro- 
 longing the life of the plate the operation of 
 damping is much less needed than on the hand- 
 press. The printing paper does not come in con- 
 tact with the plate before the instant of printing or 
 remain upon it after the operation, but is held to the 
 cylinder by the grippers and mask, and so carried 
 over the inked plate, consequently little opportunity 
 is afforded for absorption of the etching fluid. With 
 chalk paper and a new plate damping may be 
 necessary every twenty-five impressions, but as the 
 plate becomes older fifty or even one hundred may 
 be printed between the etchings. On plain paper 
 of hard surface much longer numbers may be 
 expected. 
 
Collotype and Photo-Lithography. 169 
 
 The Inking Tables, two in number, are pro- 
 vided one at either end of the machine, necessitating 
 two sets of inking rollers one of leather for applying 
 the thick ink, and another of composition for sup- 
 plying the " half-tone," the latter set requiring such 
 light application to the plate that no riders are 
 required. There are also the usual distributing 
 rollers, to which the ink is generally supplied by the 
 printer as may be necessary, the quantity being so 
 small that no actually satisfactory automatic duct 
 has yet been devised. A proper adjustment of the 
 consistency of the two inks to the requirements of 
 the plate in hand is a matter of considerable 
 delicacy, for should the ink supplied to the leather 
 rollers be too thin it is immediately removed from 
 the printing plate by the composition rollers ; these 
 again transfer it to the table devoted to the thin ink, 
 and a general " wash up " is the necessary result. 
 The ink first supplied to the leather rollers should 
 be as stiff as possible, afterwards reducing as ex- 
 perience may dictate, while to the composition or 
 tone rollers merely coloured varnish, or even varnish 
 alone, is applied, as the latter often remove enough 
 -colour from the printing plate to sufficiently tint the 
 varnish applied to their surface. The leather rollers 
 should be cleaned daily by scraping, and the com- 
 position set washed, unless the weather be very cold 
 or damp. In such cases they may be allowed to 
 stand under ink, as they will in that condition be 
 less susceptible to atmospheric changes. 
 
 M 
 
170 Collotype and Photo-Lithography. 
 
 Double Printing is sometimes resorted to for 
 work of a high class, and when negatives too thin to 
 produce good results otherwise are unavoidably used, 
 such work is usually printed on chalk paper and 
 without masking. The printing plate is usually inked 
 up twice and an impression taken ; without removing 
 the impression from the cylinder the plate is again 
 twice inked and a second impression pulled on the 
 same piece oi paper, the two images being exactly 
 super-imposed. The great gain in contrast will be 
 understood when it is considered that while the high 
 lights of the picture gain absolutely nothing, the 
 strength of the shadows is exactly doubled. The 
 results produced in this way are simply astonishing 
 when contrasted with silver prints from the same 
 negatives. 
 
ADVERTISEMENTS. 
 
 HUGO 
 
 LEIPZIG-CONNEWITZ, GERMANY, 
 
 MANUFACTURER OF 
 
 COLLOTYPE STEM PRESSES. 
 
 Awarded First Prizes at all Exhibitions where our Presses have competed, 
 $9?- "World's Exhibition, Antwerp, 1885, Diploma of Honour, -qJ 
 
 THE 
 
 KOCH COLLOTYPE STEAM PRESS IS THE BEST IN THE MARKET 
 
 MADE IN FOUR SIZES. 
 AUTOMATIC FEED BOARD, FRISKET, AND INK DUCT. 
 
 If desired, the press can be arranged also for litho or type printing 
 
 %* That these machines have been adopted, to the exclusion of all others, in 
 establishments of such repute as those of Albert, of Munich, and the 
 " Phototypisches Institute" of Berlin, are facts of the greatest significance. 
 
 PRICES AND PARTICULARS ON APPLICATION TO 
 
 HUGO KOCH, Leipzig- Connewitz, GERMANY, 
 
 OR 
 
 BEESLEY & CO., YORK PASSAGE, BIRMINGHAM. 
 
ADVERTISEMENTS. 
 
 SGHMIERS, WERNER # STEIN, 
 
 MANUFACTURERS OF 
 
 PRINTING MACHINERY 
 
 QUR COLLOTYPE MACHINES have now 
 w been introduced for upwards of twelve years, 
 during which period they have been adopted by 
 the most renowned Collotype establishments in all 
 countries. 
 
 They are manufactured in four sizes, with all 
 recent improvements, and may be ordered either 
 with or without masking frames, the utmost satis- 
 faction being guaranteed. 
 
 They may be utilised for Lithographic Printing. 
 
 Litho Steam Machines in Five sizes. 
 Bronzing Machines in Two sizes. 
 
 Further information in reply to all questions on 
 application to 
 
 SGHMIERS, WERNER & STEIN, 
 DOESENER WEG, LEIPSIG. 
 
ADVERTISEMENTS. 
 
 ESTABLISHED 1823- 
 
 LEIPSIC, GERMANY, 
 Ink Manufacturers. 
 
 SPECIALITIES- 
 
 COLLOTYPE INKS 
 
 In all ghides. 
 PRICES AND SAMPLES 
 
 FORWARDED UrON APPLICATION. 
 
ADVERTISEMENTS. 
 
 THE MAWSON 
 
 " Photo-Mechanical " Plates 
 
 ARE SPECIALLY MADE FOR 
 
 PHOTO-LITHOGRAPHERS, *8- 
 
 -Sc- PHOTO-ETCHERS & COPYING. 
 
 Collodions, Varnishes, Chemicals, and other 
 requisites for Photo-Engravers, etc. 
 
 MAWSON & SWAN, 
 
 33,SOHO SQUARE, LONDON, W., 
 
 AND 
 
 15, Mosley Street, NEWCASTLE-ON-TYNE. 
 
ADVERTISEMENTS. 
 
 GELATINE. 
 
 NELSON'S PHOTOGRAPHIC GELATINE 
 
 IS RECOGNISED AS 
 
 THE BEST for all Photographic purposes. 
 No. I. FOR DRY PLATES. 
 
 No. 2. FOR CARBON PROCESS. 
 Nelson's "Special X Opaque," for Dry Plates. 
 
 Sold Retail by all Dealers in Photographic Materials. Wholesale by the 
 Manufacturers 
 
 BED. HUH, DALE * 60., LIMITED, 
 
 14 ; DOWGATE HILL, LONDON, E.G. 
 EASTMAN'S 
 
 STRIPPING FILMS 
 
 Produce the most perfect 
 Reversed Negatives for 
 Collotype and Photo- 
 Lithography, and, when 
 used in EASTMAN'S 
 ROLLER SLIDES, 
 reduce the bulk and 
 weight immensely. 
 
 EASTMAN'S PERMANENT BROMIDE PAPER. 
 EASTMAN'S TRANSFEROTYPE PAPER. 
 
 The Eastaian Dry Plate % Film Co., 
 
 115, OXFORD STREET, LONDON, W. 
 
ADVERTISEMENTS. 
 
 AN INTRODUCTION TO 
 
 THE 
 
 SCIENCE AND PRACTICE 
 OF PHOTOGRAPHY: 
 
 BY 
 
 CHAPMAN JONES, F.I.C., F.C.S., 
 
 DEMONSTRATOR OF PRACTICAL CHEMISTRY IN THE NORMAL SCHOOL OF SCIENCE 
 
 AND ROYAL SCHOOL OF MINES ; 
 MEMBER OF THE PHOTOGRAPHIC SOCIETY OF GREAT BRITAIN, &c. 
 
 Cloth, price 3/6; post free, 3/1OJ. Paper Covers, 2/6 ; 
 post free, 2/1OJ 
 
 ILIFFE & SON, 3, St. Bride St., Ludgate Circus, London, 
 
 E.C. 
 
 THE BEST FIRST BOOK F0(\ PHOTOGRAPHERS TO BE HAD. 
 
 PHOTOGRAPHY 
 FOR ALL: 
 
 An Elementary Text Book and Introduction 
 to the Art of Taking Photographs ; 
 
 BY 
 
 W.JEROME HARRISON, F.G.S., 
 
 JTHOR OF " A HISTORY OF PHOTOGRAPHY," AND EUROPEAN EDITOR OF " T 
 INTERNATIONAL ANNUAL OF ANTHONY'S PHOTOGRAPHIC BULLETIN." 
 
 PRICE ONE SHILLING. Post free, 14 Stamps. 
 
 LONDON : ILIFFE & SON, 3, St. Elide St., Lndgate Circus, 
 
ADVERTISEMENTS. 
 
 ALL ARTICLES FOli 
 
 COLLOTYPE, PHOTO-LITHOGRAPHY, AND 
 ETCH I NG PROCESSES, 
 
 AS 
 
 PRESSES, PAPERS, INKS, ROLLERS, CHEMICAL S 5 &c. 
 
 MAY BE OBTAINED THROUGH 
 
 ROMAIN TALBOT, BRUDERSTRASSE 10, BERLIN C. 
 
 SPECIAL GENERAL PRICE LIST GRATIS ON DEMAND. 
 
 T^ 
 
 JC JL 
 
 (Established 1851.; LJfltloL'Il IN 5 (Established 1851.) 
 
 INK MANUFACTURER 
 
 SPECIALITY- 
 
 BLACK & COLOURED COLLOTYPE INKS 
 
 AND 
 
 Composition for Collotype Rollers, 
 
 F. I3RESCHCER * CO., 
 
 GELATINE WORKS, 
 
 OBERNDORF, Schweinfurt a/ Maine, GERMANY, 
 
 MANUFACTUBERS OF 
 
 IMPROVED GELATINE FOR EMULSION. 
 
 IMPROVED GELATINE FOR COLLOTYPE. 
 
 Special Gelatines for all Photographic purposes, 
 
ADVERTISEMENTS. 
 
 THE INDISPENSABLE HANDBOOK 
 
 TO 
 
 The Optical Lantern : 
 
 A COMPLETE CYCLOPEDIA ON THE SUBJECT OF 
 
 OPTICAL LANTERNS, SLIDES, AND ACCESSORY APPARATUS. 
 
 COMPILED BY EDITED BY 
 
 WALTER D. WELFORD. HENRY STURMEY. 
 
 CONTENTS. 
 
 SECTION I. 
 PART i. The Cheaper Oil Lanterns. Better Class Oil Lanterns. Double or 
 
 Dissolving Oil Lanterns. 
 
 PART 2. Single Limelight Lanterns. Biunials. Triunials. Special Lanterns. 
 PART 3. Scientific Lanterns. 
 
 SECTION II. 
 
 PART i. ILLUMINANTS Lamps, Jets, and Accessories. 
 PART 2. Lenses, Condensers, &c. 
 PART 3. Gas, Apparatus, Retorts, Purifiers, &c. Bags, Cylinders, Valves, 
 
 Pressure Boards, &c. 
 PART 4. Exhibition. Screens. Screen Frames. Reading Lamps. Desks. 
 
 Tripods. Boxes. Tables, &c. 
 PART 5. Accessories. Microscope. Polariscope. Aphengescope, &c. 
 
 SECTION III. 
 
 PART i. Carriers. Frames. Tinters, Registering Apparatus, Grooved Boxes, &c. 
 
 PART 2. SLIDE MAKERS AND SLIDE PAINTERS Notices of their Productions 
 and Specialities. 
 
 PART 3 SLIDES Temperance, Tales, Scriptural, Scenery, Nursery Tales, His- 
 torical, Entertainments, Pantomimes, Educational, Comic, Movable, Effect 
 and Dissolving, Mechanical. 
 
 SECTION IV. 
 GENERAL ARTICLES. Hints to Lecturers, by Andrew Pringle ; and other articles 
 
 4OO PAGES. NUMEROUS ILLUSTRATIONS. 
 
 PRICE 2/6 ; post free, 2/10|. 
 
 London: ILIFFE & SON, 3, St. Bride St., Ludgate Circus, 
 
ADVERTISEMENTS. 
 
 KLIMSGH & Co., 
 
 FRANKFORT-ON-THE-MAIN, GERMANY. 
 
 MANUFACTURERS AND AGENTS FOR ALL 
 
 Special Materials Requisites 
 
 FOR 
 
 COLLOTYPE & PHOTO-LITHOGRAPHIC 
 PROCESSES. 
 
 COLLOTYPE MACHINES, 
 
 ROLLERS, COLORS, INKS 
 
 Printing: and Transfer Papers, &c. 
 
 WE FURNISH ENTIRE STUDIOS AT ADVANTAGEOUS RATES 
 
 Write for particulars and Price Lists. 
 
ADVERTISEMENTS. 
 
 An unequalled guide to the latest Developments and Processes. 
 
 i ] 
 
 THE 
 
 EDITED BY 
 
 W. JEROME HARRISON, F.G.S., AND A. H. ELLIOTT, PL.O. 
 PRICE 2/- ; post free 2/4|. 
 
 ILIFFE & SON, 3, ST. BRIDE STREET, LONDON, E.G. 
 
ADVERTISEMENTS. 
 
 A GREAT DIFFICULTY, 
 
 And one experienced by all photo-mechanical experimentalists, has 
 been that of obtaining SUITABLE and RELIABLE material 
 and appliances. A prolonged visit to the best known photo- 
 mechanical establishments of Austria and Germany enables us to 
 guarantee that the articles we recommend are the best obtainable 
 for the purposes for which they are supplied. We are in a position 
 to supply 
 
 COLLOTYPE : 
 
 Collotype Machines Hand Presses Drying Boxes 
 Inks Varnishes Printing and Masking Papers- 
 Leather, Rubber and Composition Boilers Gelatine 
 Plates Iron Beds for Presses Printing Frames- 
 Reversing Mirrors and Prisms, &c., &c. 
 
 ZINC ETCHING 
 
 Zinc Plates Etching and Tapping Inks Rollers- 
 Etching Boxes Transfer Papers Printing Frames 
 Scratch Papers Whirlers Ruled Tints, Sec. 
 
 PHOTO-LITHO 
 
 SOLE AGENTS FOR 
 
 Jaffe & Albert's Transfer Ink and Papers. 
 
 The only Photo-transfer Paper to which a GOLD 
 MEDAL has ever been awarded. 
 
 USED ALMOST EXCLUSIVELY ON THE CONTINENT. 
 
 BEESLEY & CO., 
 
 York Passage, BIRMINGHAM. 
 
ADVERTISEMENTS. 
 
 THE PHOTOGRAPHERS' 
 INDISPENSABLE HANDBOOK : 
 
 A COMPLETE CYCLOPEDIA OF 
 
 Photographic Apparatus, IVlaterial^Processes 
 
 COMPILED AND EDITED BY 
 
 W. D. WELFORD AND HENRY STURMEY. 
 
 HPHIS work aims at being for size and weight the most 
 1 PRACTICALLY USEFUL of any publication on Photo- 
 graphy yet issued. No practitioner, whether professional or 
 amateur, whose time is of the slightest value, should fail to possess 
 a copy. It consists of 422 handsomely printed pages, demy Svo., 
 and 500 illustrations, crammed full of information, the result of 
 several months' steady labour. Descriptions and prices of every 
 photographic accessory, over 200 cameras, 150 lenses, 40 tripods 
 and stands, 140 plates, 40 lamps, shutters, complete sets, bur- 
 nishers, special solutions, etc., etc., etc. Numerous press and 
 other opinions sent on application. 
 
 " Will prove of great assistance." Proceedings of the Camera 
 Club. 
 
 " The Laxton of the Photographer." Photographic News 
 Almanac. 
 
 11 This is an excellent guide to the purchaser of Photographic 
 Apparatus." The Camera. 
 
 PRICE, 2/6; post free, 2/1O*. 
 
 ILIFFE & SON, 3, St. Bride St., Ludgate Circus, 
 
 LONDON, E.G. 
 
ADVERTISEMENTS. 
 
 CH. LORILLEUX S CO,, 
 Printing Ink Manufacturers 
 
 BLACK AND COLOURED VARNISHES, ROLLER COMPOSITION, ETC. 
 INKS for 
 
 GOLD MEDALS. 
 
 PARIS 1855. 
 
 PARIS 1878. 
 
 MELBOURNE 1881. 
 
 LONDON 1884. 
 
 DIPLOMAS OF 
 HONOUR. 
 
 VIENNA 1873. 
 AMSTERDAM 1883. 
 ANTWERP 1884. 
 
 PAI^IS : 16, Hue Suger. LOJIDOJI : 27, Bouverie St., Fleet St, 
 
 Works : Puteaux and Nanterre. 
 
 To Collotypists 
 
 We strongly recommend our 
 
 ROSE-TINTED 
 
 DULL ENAMEL 
 
 PflPER. 
 
 Quality the Best. 
 
 Samples and Proofs on application. 
 
 Gust.& Heinr. BeneKe, 
 
 Loban, Saxony. 
 
 HEINRICHS' 
 CELEBRATED 
 GELATINES 
 
 FOR 
 
 PI\oto-Lithograpl)y, Collotype, 
 
 ETC. 
 
 A.&M.ZMIMERMANN 
 
 SOLE AGENTS, 
 
 6 & 7, Cross Lane, 
 
 LONDON, E.G., 
 
 Or direct from the Manufacturer 
 
 CH. W. HEINRICHS, 
 
 Gelatine Works, Hoechst-on-the-Main, 
 GERMANY. 
 
ADVERTISEMENTS. 
 
 **f~ THe OLH>EST Penny 
 
 Paper in tine HiTorld. 
 
 EVERY THURSDAY ONE PENNY. 
 
 PHOTOGRAPHY: 
 
 The Journal of the Amateur, the Profession, and the Trade, 
 
 IS 
 ACCURATE, ISTEV^SY, ENTERPRISING. 
 
 EDITORIAL CONTRIBUTORS- 
 apt. W. de W. ABNEY, C.B., F.R S.; Prof. W. K. BURTON, C.E.; GEORGE DAYISON ; 
 
 CHAPMAN JONES; ANDREW PRINGLE; FRANK M. SUTCLIFFE. 
 Editor- HENRY STURMEY. Sub-editor-WALTER D. WELFORD. 
 
 The special features are: Scientific and Technical Articles by well- known 
 writers The Question Box, with a series of prizes for the senders of replies 
 Prize Competitions Snap Shots Jtems of Interest Interviews with Prominent 
 Members of the Trade; and the price One Penny. 
 
 A SPECIMEN COPY WILL BE SENT GRATIS AND POST FREE. 
 
 WHAT THEY THINK OF IT: 
 
 "Photography is a positive success." Wilson's Photographic Magazine. 
 
 " A stirring, newsy journal, which bids fair to a successful career." St. Louis Photographer. 
 
 " It is very interesting, and far ahead of the other photographic papers." GERALD STONEY, 
 Gateshead. 
 
 " I look upon Photography now as part of my weekly diet, as it suits my constitution." 
 MOORE, Dartford. 
 
 "When I have read the pages of one week's issue I am anxious to see the next." 
 F. LEWIS, Derby. 
 
 "Your new journal, like the 'Pickwick' pen, ' comes as a boon and a blessing to men.' " 
 J. C. CHRISTIE, Old Cathcart. 
 
 " You may be sure I shall prize this, my fi*st silver medal, and I shall not want to look at it 
 to remind me of Photography, as I always have this paper for dessert on Thursdays." J. W. 
 EVANS, Wolverhampton. 
 
 " I think vour paper a marvel of cheapness. I had great difficulty in getting it regularly, 
 or even at all, at first; but since I have succeeded I think all my early trouble has been liberally 
 repaid." A. C. ADERSON, Arbroath. 
 
 " I must sav Photography is proving a decided success ; it seems to be improving every week. 
 Since taking in your paper I have entirely given up a journal which is published on the same 
 subject, which, though more mature in years, still takes a leaf from its infant friend." 
 M. TILLICOUTHY. 
 
 London: I LI FFE<& SON, 3, St. Bride St., E.G. 
 
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