Another vote for either an antique (which will 99% likely need some inexpensive rehab work) or the ones Bostick & Sullivan sell. I've got two of theirs (11x14 and 16x20) and a hodge-podge of antiques (11x14, 12x20, 14x17) that all work nicely. The antiques I had to re-felt and in some cases re-hinge to get the back boards square and level. Nothing that 20 minutes and $20 at the hardware and crafts stores couldn't fix. Plus there's a cool factor to using a hundred year old contact frame to make alt-process prints.