Quote Originally Posted by Photo Engineer View Post
In spite of their words to the contrary, Ilford MGIV paper tests medium positive for incorporated developing agent(s). It is not useful to wash a developing agent out as other useful chemistry might go as well.
PE
I agree with this. There are a lot of threads on APUG insisting that MGIV does not have incorporated developer and that might be true but there are acceleration agents or something. Last night I played for quite a while with some cut up pieces of lumen prints on MGIV and they develop a dark grey very quicky when dipped in 2oz water + 1/2 tsp sodium carbonate. I can't get to full black and the development appears to exhaust fairly quickly: after the initial 15 seconds or so, no further development happens in "washing soda water".

This makes me wonder how much of the paper development with caffenol I've read about is just from alkaline solution and how much is from the homemade developer or coffee part.

I was trying to produce an extremely slow working developer for paper, and thought an old unwanted lumen print would make a good test subject. Pretty soon I was just playing with room light exposed paper strips, at my desk in room light.

I managed to produce one very interesting effect. I took a little snippet of a lumen print with whitish plant stems on it, surrounded by pinkish purple. This I dipped in the "soda water" and then quickly into a cup of coffee ( would be slightly acidic, I think) . I managed to stop the development at a lower point. Then I blasted the snippet under my desk lamp for about 15 or 20 seconds and started dipping it back and forth between the coffee and the soda.... the background only darkened a little more, but the original light colored stem turned a dark purple color. I think I might have produced something similar to the so-called Sabattier effect.. or maybe just some kind of self-masking & developer exhaustion combination. Whatever it was, I did get a reversal, even though the final result was lower contrast. I'm intrigued and will probably play around with this some more.

Do you think it might be possible for me to reduce the ph enough not to activate the developing agents/accelerants in the emulsion, or at least slow them down enough to get the process more under control? I'm interested in setting up a "snatch point" rather than developing to completion.

I guess I'll find out for myself... I'll try a lower concentration and maybe some sodium bicarbonate to restrain the ph.

Anyway, I stumbled across this thread and it is very true that modern recently made MGIV will "develop" just in water +sodium carbonate, to a dark grey but not black.