My first experiments with lith processing in 2009, after a break of some 20 years, were with this formula. I chose it because it contains no paraformaldehyde, which I was having trouble obtaining.

My only variation from this formula is that I add a very small quantity of sodium sulfite (equivalent to a small fingernail-sized amount) to Solution A to improve its keeping properties.

Stock Solution A
Water 750 ml
Hydroquinone 25 g
Potassium Metabisulfite 25 g
Potassium Bromide 25 g
– Cold water to make 1.0 litre

Stock Solution B
Cold Water 750 ml
Sodium Hydroxide 36 g
– Cold water to make 1.0 litre. (Great care is needed in mixing sodium hydroxide; always add to cold water as the dissolution is exothermic.)

Dilution for lith printing is 1 part Solution A, plus 1 part Solution B, plus 23 parts water; e.g. 40ml A, 40ml B, 920ml water. Don’t expect to develop more than two 9.5 x 12 inch prints and a test strip before it’s exhausted. Development times can be between 5 and 15 minutes at 30 degrees Celsius.