I have a hinged glass commerically made unit. Its glass sits into a stamped channel that the paper and neg goes into.
The original glass fell out a few years ago, since I hang it on the wall (I am perenially short of horizontal surfaces in my darkroom). I replaced it with a heavier glass I cut and de-sharpenned the edges with using emery paper in a palm sander.
The pedestal the paper sits on I made out of a piece of 8x10 all balck foam core board that is adhered to the stamped base. There is at least 1/2 and inch all around the foam core to the return portion of the channel on the sides.
I now place the 8x10 paper O always use to contact pint with on this platform by feel, and can then place the negs in thier print file page square to this paper. A final feel and a slow closing of the lid makes shure things stay in alignment.
I went to this path because I contact print colur negs, so the work all takes place under too dim a siafe light to tell more than if you have the white or greem side of the paper up.