648 HANDBOOK OF PHOTOGRAPHY 



change of water, return it to the tray and pour the solution back on the print. The 

 operation should be done quickly, and the tray should be vigorously rocked for about 

 1 min. to prevent any streaking of the yellow image. If some degree of streaking is 

 apparent at this point and is not too pronounced, it may be ignored. If care is taken, 

 however, no difficulty will be experienced. The print is now allowed to remain in the 

 solution for about 3 min., after which the solution is discarded, the print is washed for 

 1 or 2 min. in clear water, and then it is immersed for about 1 min. in a solution made 

 up of one part standard hypo solution and three parts water. Do not keep the print 

 longer than 1 min. in this solution, as the image at this stage is slightly soluble in hypo 

 and high-light detail may be lost thereby. Wash the film immediately for not less 

 than 20 min. in running water or in five or six complete changes of water in 

 a tray. 



The yellow image, after thorough washing, is immersed for about 2 min. in the 

 yellow toner B, and then washed in running water for about 20 min. or in six complete 

 changes of water in a tray. It is then ready for assembling. 



Assembling the Three-color Print. — The third step in making color prints by the 

 Chromatone process is assembling the finished photograph. 



The three-color images are now registered on a gelatin-coated paper (Chromatone 

 backing paper) which has been previously soaked thoroughly in water. Lay the 

 backing paper, gelatin side up, on a clean ferrotype tin, clean glass or Masonite tem- 

 pered hard board, or on any flat waterproof surface. The yellow image is placed first 

 on the paper and squeegeed firmly into place, emulsion side down, and allowed to 

 remain for a few minutes to prevent sliding while registering. The red image is then 

 placed on top of the yellow, pushed carefully into register, squeegeed lightly, the 

 register checked, adjusted if necessary, and the red image squeegeed firmly into place. 

 If at this point the two images do not appear exactly in register, the red sheet may be 

 peeled off carefully, remoistened, and registered again. It will be found easier to 

 register the red and yellow images if they are viewed through a light-blue filter. 



The blue image is then superimposed upon the other two, precisely as described 

 above, completing the color print; all prints emulsion side down. 



The collodion support of the emulsion, although extremely thin and transparent, is 

 to some extent objectionable, not only because it reduces the brilliancy of the final 

 image, but also because it tends to curl inward in drying and prevents the prints laying 

 absolutely flat. This difficulty can be avoided by removing the collodion support after 

 each transfer by dissolving it with acetone. This is best done by allowing each trans- 

 fer to practically dry before removing the collodion in order to avoid any damage to 

 the gelatin emulsion. If the removal of the collodion is decided upon, it is advisable 

 to use a weak gelatin solution between transfers to produce a more complete adhesion 

 of the partial images. 



With this process, as well as with the others so far described, short cuts are not 

 advisable and instructions issued by the manufacturers of the materials are usually 

 published after careful studies and should therefore be scrupulously adhered to in 

 order to avoid waste and disappointments. 



Since variations are introduced from time to time in the quality of the material, it 

 is advisable to request up to date information from the manufacturers. 



Gelatin Relief with Color Pigment in Suspension. Dtixochrome. — Several years 

 ago H. J. C. Deeks introduced a process for color prints on paper consisting of silver 

 bromide emulsions coated on thin celluloids from which the emulsion could be stripped 

 at a later stage. The emulsion carried in suspension, the appropriate color pigments 

 and three different emulsions were supplied, each one with the corresponding comple- 

 mentary colors — yellow, blue-green, and magenta. The printing exposure for each 

 emulsion Mas determined by comparison with a standard bromide paper. The expo- 



