I'll resurrect this old thread just to see if anyone has an opinion on the "shelf life" once mixed of Bill Williams' CD4 developer (as given in his OP)?

Or might it be "better" to treat it as one-shot ?

I use C41 film infrequently enough to make buying a C41 kit uneconomic & wasteful; acquiring CD4 and some iodide is less than the cost of a kit, and I have the other chemicals on hand, so I can have a bit of fun (and perhaps even get some decent results, although I expect imperfect results and am OK with that).