In my short darkroom career so far, I have found taping to a piece of glass (actually the toughened glass front panel of an old TV) using gummed tape works perfectly. If I was doing hundreds of prints it would be a hassle, but it's part of my routine to limit to 2 FB prints at a time (which is the size of my glass). They really get under tension as they dry and "ping" noticeably when I run the blade around the edge to cut them off. The residual tape soaks off the glass easily. Works for me. YMMV.