Last weekend's start was a comedy of errors.  I cut up some scraps of what I thought was Strathmore 400 printmaking paper ( which was really blotter paper! ).  I tried to make up 25ml of what was supposed to be 1.5% AFC, 1.5% AFO and 1.5% gelatin... but when I opened my jar of AFC it was a solid green disk at the bottom of the jar, so I used 3% AFO, and when I measured the gelatin it stuck to the plastic spoon I was using as a scoop and I end up putting in too much.  So, I ended up with 3% AFO 3% gelatin.  Anyway, I coated 5 or 6 pieces of blotter paper (!) and put them in a dark closet to dry, then got too busy to do anything more until today.

Today, first I made up an eyedropper bottle of 25% AFC using a chunk of the hardened AFC from the bottom of the jar, then I made a quick cyanotype with it and it seems to be perfectly fine ( good, because there's still a lot left in the jar! ).  I also made up a 25% dropper bottle of AFO, so now I won't need to worry about dust and dust masks and it will be much more convenient to work with.  I found the real Strathmore 400 printmaking paper.  I cut up some 5x7" pieces ( 1/16" less in each dimension so that they will fit into film or plate holders ).  Also got out my Jason Lane 5x7 plate holder and double checked that this size paper will fit, and it does.

The first real experiment was already interesting.  I coated a piece of 5x7 paper with the leftover 3% AFO 3% gelatin from last weekend after warming it in the microwave for 5 seconds to make it liquid.  Then I let it sit for only 5 minutes ( the idea was to let it cool enough to set the gelatin, but not to become dry ).  Then I took it out into the sun and exposed strips of 0, 5, 10, 15, 20, 40, 60, and 90 seconds.  Then I put it immediately into a 0.3% solution of H₂O₂.  It became a medium-dark ferric oxide color all over, with no obvious differences between the strips that had been exposed different times.  Right now it's been sitting in 1% 2-Na EDTA for about 1hr 45min and the ferric stain is probably 90% gone... it was maybe 75% cleared after an hour.  I expect it will become completely clear in another couple hours.  ( Sandy King mentioned that the reason people don't like AFO in gelatin is the yellow stain, but I suspect he may not have been willing to wait hours for it to clear... I don't care how long it takes to clear as long as it does, if it really makes the exposure short enough.  Certainly looks now like it's probably going to clear eventually. )

( I didn't think to take a snapshot at the beginning, but you can see what was a medium-brown stain is mostly gone after 2 hours in EDTA )

Pure speculation: I think the fact that it is so hard to clear the ferric stain may mean that the gelatin was hardened ( or at least disrupted so that it can no longer swell easily in water -- it's not completely clear what happens in ferric gelatin ) everywhere... even the little strip I meant to leave unexposed to sun.  I carried it out to the sun in my hand and just kept a white paper over it... and it's possible that my "unexposed" strip was exposed to enough indirect light bouncing off the white paper to cause ferrous to form in the wet gelatin.  If that turns out to be true it could be a sign that this is going to work a lot better than I hoped.

After a little more thought, I'm going to go from here with 2% gelatin solution.  I've got .5g gelatin swelling in 25ml water in a film canister and will heat and mix it soon.  Then I'll "sensitize" it by adding drops of AFO and AFC ( 1 drop per ml of solution is going to be a bit more than 1% ... so maybe I'll start with 25 drops each in the 25ml and adjust from there )