Very quick update. After confirming that what I was observing was development and not just fogging, I also confirmed that "regular" caffenol ( coffee + sodium carbonate ) used after initial development with just sodium carbonate and incorporated chemicals completed, does continue development further and does reach black.
Development with "normal caffenol" for MGIV consists of two things: the development induced by the alkaline solution and incorporated chemicals which happens very quickly, followed by slower development by the caffenol itself. The first part is strongly modulated by the pH.
My next steps will be to make "standard photograms" and then systematically vary temperature and pH. Probably next weekend!
Edit: I'm also planning to follow up on PE's suggestion of a neutral or basic fixer, well diluted. Need to make an order for that.
Last edited by NedL; 01-21-2013 at 03:22 PM. Click to view previous post history.
Reason: forgot to mention