This formula produces rich green tones by combining the effects of iron blue toning and sulfide sepai toning. It must, however, be employed carefully and with particular attention both to the directions outlined below and to cleanliness in handling prints throughtout all steps of the process. The formula is not adaptable to all types of paper and surfaces and is suggested for use only with the following Ansco papers: Brovira, Velvet and Kashmir White; Cykora Kashmir White’ Cykon Kashmir White and Matte White’ and Projection Proof.
Solution 1
| Ferricyanide | 40 g |
| Water | 1 L |
| Ammonia .91 S.G. (25% in weight) | 15 ml |
Solution 2
| Ferric Ammonium Citrate | 17 g |
| Water | 1 L |
| Hydrochloric Acide Conc. | 40 ml |
Solution 3
| Sodium Sulfide | 2 g |
| Water | 1 L |
| Hydrochloric Acid Conc.* | 10 ml |
*Do not add the Hydrochloric Acid to Solution 3 until immediately before use.
Black-and-white prints to be toned should be darker and softer than a normal print, using approximately 25% overexposure on the next softer grade of paper. Development of the print should be carried out in a suitable developer (A125 or A135) with particular attention given to avoid underdevelopment or forcing the print with overdevelopment. Prints should be fixed as usual, throughly washed and completely dried before toning.
Prints to be toned should be first soaked in cold water until limp and then placed in Solution 1 until bleached. This operation should be completed in 60 seconds or less, and the bleached prints immediately transferred to running water where thorough washing (at least 30 minutes) is effected.
Bleached prints are then placed in Solution 2 for 45 seconds to one minute, toning being permitted to continue until the deepest shadows are completely toned. Prints should then be washed briefly (4 to 6 minutes), excessive washing being undesirable in view of the solubility of the blue image. If wash water is slightly alkaline, it should be acidified somewhat with acetic acid to prevent degradtion of the blue tone during washing.
All solutions should be prepared within 24 hours before use. Great care should be taken to avoid contamination of Solutions 1 and 2. Even slight traces of Solution 1 carried over on hands or prints into Solution 2 can cause blue stains. Solution 3 should be used in a well-ventilated room, preferably near an open window or exhaust fand to lessen chance of inhaling hydrogen sulfide formed in the solution.
From Ansco Formulas for Black and White Film by GAF, 1948 – Formulas are provided for historical reference. They may not work well with modern films and papers. Some of the chemicals can be dangerous. As with all photographic processes, be careful.
