COLOR PHOTOGRAPHY 651 



The next operation is the removal of the emulsion which has not been affected by 

 the developer. This is obtained by immersing the color films in a tray of hot water, at 

 about 125°F., to which a few drops of glacial acetic acid have been added. 



It is not advisable to treat the three films all together because of the danger of 

 damaging the delicate relief image by sliding one over another. The development of 

 each film in hot water can be carried out in succession or in separate trays. Each film 

 should be given a few rinses in hot clean water until no appreciable trace of color drains 

 out. 



The bleaching of the silver image is next carried out in a solution made up as 

 follows : 



Stock solution H 2 oz. 



Stock solution D 2 oz. 



Water 8 oz. 



The bleaching time is about 5 min., or it should be continued until every trace of 

 black silver has disappeared. 



Following the bleach, the image should be given a wash of 5 or 10 min. in running 

 water. 



At this stage both the yellow and magenta images can be put away to dry. The 

 blue-green image, however, should be given a 3-min. treatment in a solution made up 

 as follows: 



Stock solution E 1 oz. 



Water 8 oz. ■ 



Then it should be briefly rinsed in cold water, after which it can be also put away to 

 dry. 



A certain amount of correction to improve the color balance can be carried out 

 before the emulsions are dry. For this purpose it is best to superimpose the three wet 

 images together on the bottom of a white enameled tray to judge the over-all balance. 

 In case of a predominance of one color that particular film can be further treated in 

 hot water until reduced sufficiently. It is best, however, to avoid this partial correc- 

 tion as much as possible. 



The assembly of the three colored images on the final paper is carried out in the 

 following manner: The yellow film and a piece of final paper of the correct size are 

 immersed in cold water for about 5 min. The two are withdrawn together carefully, 

 avoiding air bells, and squeegeed with a flat squeegee to remove the excess 

 water. Then the two are placed between blotting paper under a heavy pressure, such 

 as a letterpress. After about 10 min. the sandwich is removed from under pressure 

 and placed to dry in a warm stream of air. When completely drj^ the celluloid sup- 

 port will readily detach, leaving the yellow image on the final paper. 



The blue fUm is now soaked in cold water for about 5 min., after which the paper 

 carrying the yellow image is also passed into cold water for exactly 1 min. and the two 

 brought into contact and removed together from water, carefully avoiding air bells. 

 The two are squeegeed lightly together, carefully expelling any air bubbles which 

 might exist, and the correct registration is assured by sliding the film gently. Again 

 the sandwich is placed between blotting paper and under pressure for another 10 min. 

 The drying is then done by gentle heat. 



The red image is finally transferred to the other two in the same manner. 



The surface of the finished colored print will assume a semimatte effect if soaked for 

 several minutes in warm water and allowed to dry in cool air. 



The Duxochrome process lends itself to the making of color transparencies. 



The material for this process is marketed in the United States under the trade 

 name of Colorstil by Ruthenberg Color Photography Company, Hollywood, Calif. 



