I've been using the following formula as an RA4 developer (found on http://www.bonavolta.ch/hobby/en/photo/c41_ra4_chemicals.htm): Water (Room Temp) 750.0ml Triethanolamine 6.0ml Sodium Sulfite, Anh. 1.0g CD-3 5.0g Potassium Carbonate 40.0g Sodium Chloride 0.5g Tinopal SFP 0.5g Water to make 1.0L Except I use a different (Sprint Systems) or no brightener, Tinopal not being available to me. I find that while this formula is apparently designed to use at 95 deg F for 1 minute, it seems to work best at 100 deg for 1.5 minutes, leaving me to wonder whether the formula can be improved. Any suggestions? I thought of maybe boosting the CD3 a bit as that has produced results in other areas (eg., small tank processing of ECN-2), but otherwise, I'm at a loss. I like to mix my own chems as it is convenient and extremely economical. Any suggestions/comments on the above formula or alternative homebrew RA4 formulae would be gratefully received.