306 PHOTOGRAPHIC FACTS AND FORMULAS 
for five minutes and dried. After exposure the image 
should be seen in a brown colour on the yellow ground of the 
paper, and should be rapidly washed until all trace of the 
sensitiser is removed. Then it should be allowed to soak in 
water at 25° to 28° C. (77° to 82° F.) for 10 minutes, placed 
face up on a damp pad or sheet of glass, the surface moisture 
removed, and the ink applied. The further treatment is as for 
the bromoil process. 
AQUARELLE PRINTING.—The preparation of the prints is 
exactly the same as for oil printing, but, instead of using oil 
pigments, thick water colour pigments are used. 
OrLocrAPH.—This is a modification of the bromoil pro- 
cess, in which a plain gelatine paper is used. A good bromide 
print is soaked in water for 5 minutes, then squeegeed into 
contact with the gelatinised paper, which has been soaked for 
2 to 2%4 minutes at 16° C. (60° F.) in the following: 
Potassium bichromate ll¢g 84 er. 
Potassium ferricyanide 7.52 58 gr. 
Potassium bisulphate 0.625 g 3 gr. 
Potassium bromide 7.38 58 gr. 
Chrome alum 16¢ 11 gr. 
Water 1000 ccm 16 oz. 
The print and the paper should be allowed to remain in con- 
tact under slight pressure for 20 minutes, then separated, and 
the print washed, when it can be redeveloped and used again. 
The gelatine-coated paper, after stripping, is placed in water 
at 32° C. (90° F.) for a few minutes; then a relief begins to 
show, and it can be inked up as usual. Either single or double 
transfer carbon paper may be used for the gelatinised paper. 
MaxkinGc BromoiL TRANSFERS.—Presses are obtainable 
commercially, which practically consist of two superimposed 
rollers, with flat beds on each side for supporting the transfer 
