toner
Kodak T-1a hypo-alum sepia toner
Handle chemistry safely
Wear gloves and eye protection, work with good ventilation, and read the supplier’s safety data sheet before use. Hazard information here is a summary, not a replacement for it. Dispose of all photographic chemistry correctly, in line with local laws and your local authority’s guidance. Never mix waste solutions, and check the supplier’s safety data sheet before disposing of anything.
Ingredients
| Sodium thiosulfate pentahydrate | 480 g |
| Potassium alum (dodecahydrate) | 120 g |
| Silver nitrate | 4 g |
| Sodium chloride | 4 g |
| Water to make | 4.0 L |
Notes
Hot toning bath (49 °C) for fixed and washed prints. Dissolve the hypo, then add the alum solution. Separately dissolve the silver nitrate before adding the salt, and add the milky result to the hypo-alum bath. Kodak notes that toning lowers density and contrast, and warns against going above 49 °C or toning for more than 20 minutes.
Source
Processing Chemicals and Formulas for Black-and-White Photography (Kodak Publication J-1), 7th edition, Eastman Kodak Company (1977), p. 46
Amounts as published. Chemical forms (anhydrous, monohydrate and so on) change the weights, so match the form listed.