It might be expensive but they have an iron on fleece that patterns are using for purses that would stiffen them for you but I think I would have husband or maybe yourself if handy with nail gun, tack together 1x1 or 1 x2 frames (depending on how big the finished products are and staple them stretched like a canvas. Easy to hang, light weight and professionally finished especially if you use a solid color border it would kind of look like a matte board. You could also stretch over cardboard or foam core if not too big and just tape to the back with clear box tape.