For maximum sharpness at some loss of fine grain. Emulsion speed approximately doubled (Test first!).

Solution A

Pyrocatechin 80.0 g
Sodium Sulphite anhydrous 12.5 g
Water to 1 litre

(Pyrocatechin is also known as Catechol.)


Solution B

Sodium Hydroxide 100.0 g
Cold Water to 1 litre


Note : The excess Pyrocatechin with minimum sulphite gives the surface development effect.

Working Solution
25 ml of A, 15 ml of B, water to 1 litre.

Develop 15-20 mins @ 20ºC depending on film. The dev. keeps reasonably in stock, but deteriorates rapidly once mixed. Use once and discard.