The DARKROOM COOKBOOK, Third Edition

314 THE DARKROOM COOKBOOK
STOCK SOLUTION B
Cold water, 500.0 ml
Sodium chloride, 75.0 g
Sulfuric acid, concentrate, 16.0 ml
Water to make 1.0 liter
STOCK SOLUTION C
Sodium bisulfi te, 1% solution, 1.0 g
Water, 100.0 ml
Harden the fi lm for 2 to 3 minutes in Kodak SH-1 Formalin Supplementary Hardener. After
hardening, wash for 5 minutes. Bleach the negative for 3 to 4 minutes using equal parts A and
B (the solutions should not be mixed until ready for immediate use, since they do not keep
long after mixing).
When bleaching is complete, immerse the negative in Solution C to remove any brown
stains. Rinse the negative well, and redevelop in a strong light (not direct sunlight). Use a nonstaining
developer such as Kodak D-72, diluted 1:2.
NOTE: Developers containing high sulfi te and low alkali concentrations (e.g., Kodak D-76)
should not be used for redevelopment. The sulfi te tends to dissolve the silver image before
the developing agents have had time to act on it.
Caution: Add the concentrated sulfuric acid slowly with constant stirring to the cold solution
of sodium chloride.
FORMULA #193
Kodak SH-1
Formalin Supplementary Hardener
This formula is recommended for the treatment of negatives that would normally be softened
considerably by chemical treatment during the removal of several types of stains, or by intensifi
cation or reduction techniques.
Water, 500.0 ml
Formaldehyde, 37% (formalin), 10.0 ml
Sodium carbonate, monohydrate, 6.0 g
Water to make 1.0 liter
After hardening for 3 minutes, negatives should be rinsed and immersed for 5 minutes in a
fresh acid fi xing bath and well washed before treatment.
Caution: Formaldehyde is highly toxic. Use in a well-ventilated area and exercise all handling
precautions. Unless your mixing area has an effective fume hood it is highly recommended
that you mix formaldehyde outdoors, and even then an appropriately rated fume mask should
be used.