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.
Preparing The Gold Bath. The toning bath is prepared as follows: Into a 2-quart bottle pour 48 ounces of water, and of Stock Solution No. 1 add 1 1/2 ozs., of Stock Solution No. 2, 2 ounces; then thoroughly shake the bottle containing this compound and allow it to stand for at least twelve hours before using. A longer time will do no harm.
333. When ready to tone add gold enough to make the speed of the bath six to eight minutes. Watch the bath closely to see that the highlights do not bleach. If they do bleach, add more alkali, regardless of the color of the litmus paper. Tone the prints in this bath to a purple, leaving considerable warmth in the shadows. After toning place them in clear water.
Caution. If prints are toned too fast in the gold bath, they will be flat. The whites should be thoroughly cleared and brilliant when they come from the gold bath. Too much alkali, or a slow bath, will give flat prints and muddy whites.
Washing After Gold Bath. Wash the prints in five changes of clear water, handling them over in each water. In the second wash water use three ounces of saturated solution of alum to the gallon of water; or, instead of alum, 1 ounce of salt to the gallon of water; or slightly acidify the second wash water with acetic acid. After this "short stop" washing, the prints must be washed in three more waters. Unless they are well washed before going into the platinum bath, the platinum will precipitate on the tray and not on the print. After prints are washed, tone in the following bath:
Keep this solution corked and in a dark place. 337. Prepare the bath as follows:
Platinum Stock Solution.................. ...
1 1/4 ozs.
Tone in this bath until the highlights are perfectly cleared, leaving but the slightest trace of warmth in the shadows. Carrying too far in this bath is likely to flatten the tone and injure the brilliancy of the print.
Washing After Platinum Bath. After the prints are all toned through the platinum bath, it is quite important to wash them thoroughly to remove the remaining acid, because if carried into the hypo bath it will produce sul-phurization and yellow whites. Wash through five changes of clear water and fix in the following bath:
Fix fifteen minutes, handling the prints constantly to insure even and thorough fixing.
Salt Bath. After the prints are fixed, place them in a salt bath composed of 4 ounces of salt to the gallon of water. Use plenty of solution and always keep the proportions the same. Allow the prints to remain in this bath about five minutes, picking them over and over during this time.
Final Washing. The final washing is more important with collodio carbon than with any other papers, owing to its weight and thickness. The prints should be carefully washed through twelve or fifteen changes of clear water, handling each print separately, after which they may be mounted or laid out to dry.