I was wondering -- I use imagesetter imaging film in a small offset printing business that I have. Often the film gets messed up (someone forgot to proof the page, etc). If I bleach the emulsion off of the films that cannot be used to make printing plates, will the substrate that remains be suitable for coating with emulsion without further preparation?

This would mean that instead of the used film being hazardous waste, the bleached off emulsion would be, and I would have to figure how to dispose of it, but the clean substrate could be used for coating if I ever get around to making my own emulsions. And I have quite a lot of the stuff.