Energetic positive developer giving vigorous results. Producing pure black to blue-black tones on chloride paper, and pure black tones on bromide enlarging paper.

Focal paper developer for blue-black tones, working solution
Mix chemicals in order.
Sodium sulphite anhydrous25grams
Sodium carbonate anhydrous37.5grams
Potassium bromide0.5gram
Water to make1liter

Do not dilute as solution is ready for use.

Times of development:

  • For contact printing papers (gas-light): 45–60 seconds.
  • For enlarging papers (chloro-bromide and bromide): 1.5–2 minutes.

Keeping qualities and use: The solution keeps well and is very economical in use.

Note: To increase the capacity of the developer for blue-black tones on contact printing papers (gas-light), and pure black tones on enlarging papers (bromide), add a developer improver.