Monobath Formula

FX-6a (G Crawley)

Sodiun Sulphite (anhyd) 50gms
Hydroquinone 12gms
Phenidone 1gm
Sodium Hydroxide 10gms
Sodium Thiosulphate 90gms
Water to I litre

The Thiosulphate can be varied betweeen 70gms to 125gms to alter sftness, and increasing Hydroquinone to 15 - 17 gms will increase the contrast. Crawley states that this formula gives normal film speeds, processing is normally around 4 to 5 mins at 20C
and between 9 - 12 films per litre capacity.

See British Journal of Photography Annual 1972, page 162, article: Rise and Fall of the Monobath, also page 231 for details of how to use the Monobath