This section is from the book "Complete Self-Instructing Library Of Practical Photography", by J. B. Schriever. Also available from Amazon: Complete Self-Instructing Library Of Practical Photography.
Printing. The print plate marked blue is then soaked in the blue dye bath for about fifteen minutes. It is then washed under a stream of water until there is no color in the water running off it. A piece of plain gelatin-coated paper, a little larger than the plate, is then soaked in cold water until saturated, when the print plate is put under the water and the two films brought into contact. All air-bells and superfluous water must now be removed with a flat squeegee, rubbing from the center outward. The wet print should be protected by covering with a thin sheet of celluloid or rubber, during squeegeeing. Now lay upon the print a few thicknesses of damp blotting paper or a wet pad of felt, on that a plate of glass, and then a seven pound weight. Printing will be complete in ten to twenty minutes.
Examine the print by turning up one corner, and in order to insure perfect contact, should it be necessary to replace the print for further printing, immerse that corner again into water and again squeegee down. When the print is sufficiently deep, remove from the print plate and hang up to dry. If it is desired to make several duplicates, the print plate must be dyed up between each print, by placing in the dye-bath for about five minutes.
1232. When the blue prints are dry proceed to dye up the red print plate, and when sufficiently dyed and washed, put a blue print into water until limp, then bring the red plate into register upon it, and squeegee as before. Registration is best accomplished by holding the picture up to a strong light and looking through it. When the violet prints are dry, the yellow print plate is dyed up. The yellow dye is slow in action, so that the plate must soak in it for quite half an hour before transferring. Registration of the yellow print can only be satisfactorily done by daylight.
1234. Modified "Pinatype." - The following method reduces the operations of the original process and will be found to work successfully. When making the positives from the set of three-color negatives, they must be developed with an alkaline developer such as metol-hydroquinon. When dry, sensitize in the following bath:
1235. Sensitizer for Red and Blue Print Plates. -
Bichromate of Ammonium........................................
Liquid Ammonia (880).............................................
Immerse for four minutes and dry in the dark.
1236. When dry, put the bichromatized positives into printing-frames, back up with black paper or felt, and expose to daylight. Exposure must be made through the glass. The method for timing the exposure mentioned in the former process will be found useful for this. The yellow plate, however, will require twice the exposure given to the red and blue.
1237. After exposure, well wash out all the bichromate and then remove the deposited silver from the film with the hypo-ferricyanide reducer. After being thoroughly washed, the plates are ready for dyeing up and printing from.