I was making up a litre of this paper developer tonight (I like the colour it produces) using the formula below, when I suddenly thought, That seems an awful lot of carbonate ... so I regoogled around and found variations. Water 750ml Metol 2.7g Sodium sulfite (anhy) 40g Hydroquinone 10.6g Sodium carbonate (anhy) 75g KBr 0.8g Water to 1000ml The variations I found are only in the amount of Sodium carbonate. The one above is in the Darkroom Cookbook 3rd Ed. as well as elsewhere (including APUG) However I've also seen it given as 75g carbonate (monohydrate) and 87g carbonate (monohydrate) I think 75g anhydrous = 88g monohydrate and that this is why there are variations in the formulas I found (as a result of transcription errors), but I might be wildly wrong on both of course So, two questions: 1 Anyone (Ian Grant?) know the "definitive" formula? 2. What are the practical consequences of varying the level of carbonate in a developer such as this? WIll ~10g or so really make that much difference?