The DARKROOM COOKBOOK, Third Edition

292 THE DARKROOM COOKBOOK
Tone until the print appears deep blue. Then remove and wash until the tone changes
to green. After the green tone appears continue to wash for 10 minutes. Treat the print with
Hypo Clearing Agent (HCA) and give a fi nal wash of at least 1 hour.
If a yellowish stain appears you can remove it by placing the print in the following solution:
Ammonium sulfocyanide, 1.6 g
Water at 68F/20C, 285.0 ml
This should be done before treating the print with a washing aid and giving the fi nal wash.
Caution: Add the acid to the water, never add the water to the acid.
Protective Toners
FORMULA #157
Kodak GP-1
Gold Protective Solution
Water, 750.0 ml
*Gold chloride, 1% solution, 10.0 ml
�Sodium thiocyanate, 10.0 g
Water to make 1.0 liter
*To make a 1% solution, mix 1.0 gram of gold chloride with 100.0 ml of distilled water. Gold chloride
is deliquescent and rapidly absorbs atmospheric moisture. The solid may have liquefi ed by the
time you wish to use it. Since you will be transferring it to a water solution prior liquefaction is not
detrimental. However, when gold chloride liquefi es, some of the liquid clings to the container cap.
Because of the small amount used it is important that all of the residual gold chloride is salvaged.
�An equal weight of potassium thiocyanate may be substituted.
Add the gold chloride 1% stock solution to 750.0 ml of water. Dissolve the thiocyanate
separately in 125.0 ml of water. Then add the thiocyanate solution slowly to the gold chloride
solution while rapidly stirring.
Using the Toner: Immerse the well-washed print for 10 minutes at 68F/20C or until a just
perceptible blue-black tone appears. Then immerse in a washing aid and wash for 1 hour.
Toning time can be increased up to 20 minutes for increased blue-black tone.
Capacity: Approximately thirty 8 � 10 inch prints can be toned per gallon. For best results,
mix immediately before use.
NOTE: Due to the cost of gold chloride the best method for obtaining a 1% solution is to purchase
it premixed from Photographer’s Formulary.
Caution: Work in a well-ventilated room and wear protective gloves when mixing and using.