Formula for developer that produce grain comparable with that obtained with the popular paraphenylene-diamine-glycin developer (see Germain Fine Grain Formula), but Kodak D25 developer is non-toxic and non-staining.

IngredientQuantity
Mix chemicals in order.
Metol
7.5
grams
Sodium sulfite anhydrous
100grams
Sodium metabisulphite15grams
Water to make
1
liter

Do not dilute. Develop for 15–20 minutes at 20°C. At 25°C the average development time is about 11 minutes in a tank and the properties are approximately the same as those of Kodak DK20 developer at 20°C.

If it is not essential to obtain the minimum graininess, or if it is not convenient to work at the higher temperature, use half the specified quantity of sodium bisulphite (that is 7.5 grams instead of 15 grams). The developing time will then be approximately 14 minutes at 20°C. Graininess will be intermediate between that for Kodak D23 and Kodak D25.

For replenishment, add Kodak Replenisher DK25R, at the rate of 37ml per roll for the first 12 rolls processed per liter and 22ml per roll for the next 12 rolls processed per liter of developer. After 25 rolls, loss of shadow detail becomes excessive and the developer should be considered exhausted and discarded at this point.