Chlorhydroquinone is used as a developing agent in this DuPont formula, to produce warm black and brown tones on Varigram paper.
|Mix chemicals in order.|
|Sodium sulfite anhydrous||16||grams|
|Sodium carbonate anhydrous||16||grams|
|Water to make||1||liter|
Dilute stock solution with water 1:1 for use.
It is necessary to develop for 4 minutes at 20°C to obtain the maximum black of the paper, at which time the tone is perceptibly warmer than with DuPont Du55D. Shorter development times with increased exposure will sacrifice the maximum black to an extent, but warmer tones are obtained.
Prints developed in this developer, when toned, will give warmer tones throughout the series than when Du55D is used.