Chlorhydroquinone alone is not often used as a negative developer, but the following formula gives good results.
|Sodium sulphite anhydrous||100||grams|
|Water to make||1||liter|
|Mix chemicals in order.|
For strong contrast, dilute with 3 parts of water. For softer negatives dilute 1:5. Add 5 mililiters of 10% potassium bromide solution to 0.5 liters of working solution.
The image appears in 20 seconds and development is complete in 4–5 minutes at 18.5°C.