I've recently set up a basic black and white darkroom, with a Beseler 23c. I'd like to try enlarging with glass holders, but can't afford the $200 the holders seem to cost on ebay. I was wondering--would it be possible to just sandwich the negatives between glass and have a cardboard mask? It seems like if I got two pieces of glass big enough, it would do the job fine...right? Does this sound feasible? Or am I overlooking something?