Distilled Water @ 53° C	500 ml
Ferric Ammonium Citrate	8 g
Potassium Ferricyanide	8 g
Acetic Acid 28%	265 ml
Water to make	1 L

Mixing instructions: Add chemicals in specified sequence.

Use: Prints should be fixed in a non-hardening fixer. You may also want to reduce the contrast of the prints, as toning will have an intensifying effect. Immerse the prints in undiluted toner solution at room temperature until the desired effect is achieved. Wash in slightly acidified water (a few drops of acetic acid will do) to deepen the blue, or use plain water to diminish the tone. For blue-gray tones bathe washed prints in a 5% solution of borax (5g. per L).