Instructions for use: a) Renew the developer and fixer simultaneously every 3 weeks or when the developer turns brown. b) Cover containers after use to avoid oxidation of the baths due to air. c) Store the solutions to be diluted already mixed, rather than concentrated and open, in order to avoid contact of the chemical solution with air and its consequent rapid oxidation. Concentrated products to be diluted for manual development. Each 240 ml dose of developer yields 1 litre of solution.