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.
511. Aristo Self-Toning Paper must be printed in daylight. The printing should only proceed to a point slightly in excess of the depth required in a finished print, thus rendering it a quick printer in addition to its self-toning advantages.
512. It has great latitude in printing and secures full values from negatives ranging from soft to medium intensity. It will be observed that the amount of salt in the water will govern to an extent the depth of tone.
Printing. Print a very little darker than the results desired in the finished print.
Salt Bath. After printing place the prints, one at a time, face down, in a bath composed of:
515. Employ at least one quart of this bath for two dozen cabinet prints. Allow the prints to remain in the salt bath about five minutes, keeping them face down. See that they are well separated by handling them over four or five times, flattening them a little each time by pressing to the bottom of the tray. This will, to a certain extent, prevent curling.
516. Use trays large enough to maintain the bath at a depth of never more than one-half inch. Keep the prints as flat as possible, care being taken that they are frequently separated to give the salt free action over their entire surface. The temperature of the bath should be about 75°. Never should it be used cold.
\, 517. As prints are toned, transfer them to a tray of clear water. When toning has been completed, put them through a solution of carbonate of soda, to prevent bleaching, and also to neutralize the prints. For this solution use one-half dram carbonate of soda to 64 ounces of water, handling the prints over five minutes in the carbonate of soda, after which transfer them directly to the fixing bath.
Hypo Bath. Place the prints directly from previous bath into the following fixing bath: Hyposulphite of soda, 30 hydrometer test, or one ounce of hyposulphite of soda crystals to each ten ounces of water. Do not use less than one quart of this bath for a small number of prints. Allow the prints to remain in the hypo bath fifteen minutes, keeping them face down and well separated by handling.
519. From the hypo bath throw the prints into the salt wash (four ounces of salt to the gallon of water), handle them over in this bath for five minutes; then wash in twelve changes of water, allowing five minutes in each.
Note (A). Trays for Aristo Self-Toning Paper should be thoroughly scoured with salt and rinsed well before using. Washing trays with alkali retards the toning.