After washing for 10 to 15 minutes, tone in the following at 65 degrees to 70 degrees F.:
| Avoirdupois | Metric | ||||
| B. | Ferric Alum (Ferric Ammonium Sulphate) | 4 | lbs. 2 ozs. | 2000 | grams |
| Potassium Bromide | 2 | lbs. 2 ozs. | 1000 | grams | |
| Hydrochloric Acid (concentrated) | 13 | ozs. | 400 | cc. | |
| Water to | 50 | gals. | 200 | liters | |
Time of Toning
Toning should be complete in from 3 to 5 minutes.
Time of Washing—Ten to fifteen minutes.
If the highlights are stained blue, or if the image will not completely tone in the shadows, this is due to insufficient washing after bleaching. When bleaching, it is important to examine the film as little as possible, otherwise streaks are liable to be produced due to the action of the air at those parts where the solution drains off the film. It is also important to tone immediately after bleaching and washing.
Life of Baths
Bleach A.
Providing the solution is screened from the light and kept covered to prevent the undue escape of ammonia, the bath keeps fairly well, but if it shows any signs of weakening, it should be revived by the addition of a further quantity of ammonia equal in amount to that originally used. If so revived at intervals, 50 gallons will bleach 40,000 feet of film before exhaustion.
Solution B.