That's pretty clever using film. I have quite a few old 8x10 sheets laying around. Hey, after fixing the film, do you remove the gelatin coating or do you just leave it?
I'm going to try spirit sensitizing. I'm waiting for ammonium dichromate to come in as it is apparently best to use with isopropyl alcohol (which I have heaps of...I can't source any acetone up here so I gave up on that)...the sad thing is that I have lots of potassium dichromate (from kallitype printing) on hand, but apparently, it and isopropyl alcohol don't work well together for spirit sensitizing...any experience with this?