Finally! I've made up a screen plate for my autochrome experiments from corn starch dyed with sharpie marker dyes. It is not very good, but it'll do for rough experiments. I'm going to make another today (hopefully more prescisely) and I'm hoping to test it soon. I'm going to try to register the mask to the film, expose, process and re-register. I'm not going to do this in-camera as of yet; I'll be making contact prints from some old slides. What I need are reccomendations for inexpensive sheet films that have good exposure latitude, medium to medium fine grain and reversal-process well (and have a clear or almost clear base). Any and all reccomendations wuold be appreciated. Thanks!!!