Retains straight edges, the edges do not collapse when cut. Used in presentations, framing, mounting some art work ,signs etc... Foam Board is temporary and not intended for long term use. Foam Board warps in time and the warping is unavoidable. The surface is sensitive to moisture. Use inside installations and signs.If the foam boards warp, turn them upside down put weight on them.It will get back to normal shape within 24hrs. White Foam Board has clay paper surface on both sides. It’s acceptable to glue. Can draw on it, use with markers, not good for painting on because it blisters. Moisture is not good for foam boards. Keep them dry.