Formulary's Universal Concentrate is an economical Hydroquinone-Phenidone developer, which gives good contrast in films. The chemicals are used to prepare a stock solution which is diluted 1:19 for film. This developer is also an excellent paper developer, providing neutral tones, deep blacks and a pleasing tonal gradation. The stock solutions are usable for 4 to 5 months after mixing. The working solutions are one shot. A 1 liter kit is used to make 5 to 20 liters of working solution depending upon dilution's used.