Quote Originally Posted by holmburgers View Post
Something I've always wondered, how can a vacuum frame keep a paper flat and the negative flat? It seems that no suction would get to the negative, unless it was much bigger than the paper and had vacuum holes around the edges??

Confused in Kansas,
The frame sucks a rubber or vinyl membrane against glass, with the paper and negative between the two.

I had similar questions until I dove in and built one myself from two large picture frames, a piece of glass, a sheet of vinyl a vacuum pump, a pack of weatherstripping, some rubber tubing and a stapler. I've subsequently added hinges. Fairly economical, works exceedingly well.

-- Jorj