This section is from the book "Modern Photography In Theory And Practice", by By Henry G. Abbott. Also available from Amazon: Modern photography in theory and practice: A hand book for the amateur.
After washing tone in the following bath:
Single Toner................................................................ 2 drams.
Platinum.................................................................... 1 dram.
Prints should be toned in this bath until all trace of of red has disappeared from the deepest shadows. If the toning is not carried fully this far, you will not get pure whites, or clear shadows but prints will come out after fixing a dirty, muddy, green color, with no brilliancy. Throw prints from toning bath into clear water until all are toned. Then wash in four changes of clear water, handling prints over in each wash water to thoroughly eliminate all acid before fixing. Then fix in a plain hyposulphite of soda bath, eighteen grains strong to the ounce, hydrometer test, for twenty minutes, handling prints during fixing to insure perfect results. After fixing, wash in ten to fifteen changes of clear water, or one hour in running water, handling prints over occasionally to insure thorough washing.
In toning Aristo Junior in the single toner for olive-black tones, it is handled just the same as Aristo Platino, with the one exception, flattening the prints in the first wash water, as described on page III. In handling Aristo Junior and toning in the single toner, print fully as dark as for Aristo Platino. The prints will tone some slower than Platino, owing to the heavier gloss surface but when finished and burnished with a hot burnisher, will turn a beautiful, rich, olive-black print, equal to any gloss carbon made, fully as permanent and much finer than any gold tone print.
I. In many places the water is impure and red spots make their appearance. In trouble of this kind, add to every gallon of the first wash water, three ounces of a saturated solution of sal soda. Handle prints over in this water five minutes. It will do very little good in any but the first wash water.
2. If prints when put into the toning bath bleach or cut out the high lights, spoiling the delicate half tones, the addition of from one to two drams of platinum solution to the toning bath will remedy the trouble.
3. Your toning bath can be strengthened by adding two drams of platinum solution and one dram single toner, always watching your bath to see that it is working right.
4. When bronzing shows in the shadows after prints are finished, the best remedy found is the sal soda in the first wash water. It softens the emulsion enough to allow the silver to wash out more freely in the heavy shadows, as well as allowing the toning bath to penetrate the same and thus remove the trouble.
5. The best results are obtained by using fresh toning bath every time. In no case, ever use more than one-third old bath over.
6. To remove red spots on prints toned with single toner, dilute the stock single toner solution with equal parts of water and apply to spot, but not until print is fully toned.
7. Prints should be thoroughly washed in four changes of water after toning, before fixing, as the toning bath is very acid and if this is carried into the fixing bath it is liable to cause muddy whites and prints with no brilliancy.
8. Never use the platinum tray for anything but single toner and platinum toning.
9. All wash waters and toning baths should be kept in a temperature of 65 or 70 degrees during cold weather.
10. Last but not least, use judgment in all your work and do not condemn toning solutions, paper, etc., just because you do not have success at first; remember that others are working them successfully and you should be able to do the same.