Developer for blue/black tones on contact papers (such as Gevaert “Ridax” paper).

IngredientQuantity
Metol
2.5
grams
Sodium sulfite anhydrous
25grams
Hydroquinone6grams
Sodium carbonate anhydrous
40
grams
Potassium bromide0.5
grams
Water to make
1
liter
Do not dilute.

Develop papers for 1 minute at 20°C.