Paul, I just realized that both of the postings were you. I've got a vacuum back from and old process camera you can have. About 24" x 24" +- ?? Was going to use it in my photo darkroom but never got to it. I'm an old printer (lithographer). Seems we have similar backgrounds. Here's another idea for you. Saw this done @ Color Media in Burbank, CA. They don't make enormous negs, they make enormous mural size prints. They project 4x5 negs or trans on to photo paper on the wall. The entire wall is a vacuum back. BTW it's in a large open dark room. Type R or C prints from a huge roll. 10" X whatever. and larger. -Steve