What kind of density board foam board is good for cross-stitch backboard?

KT board is not suitable for painting and calligraphy cross-stitch mounting, for the simple reason that KT board or foam board is mainly waste, mainly bright white. Its advantages are low cost, quick and convenient processing and no effort. Its disadvantages are fast aging, no load-bearing, inability to eat nails, and poor adhesion to objects (painting and calligraphy are not carved for a long time), so painting and cross-stitch mounting can not be used as plates at all. The commonly used material of raft is high-density board. The more you use it, the stronger it becomes, and the plywood usually does not deform! Really good paintings are made of high-grade density board or high-grade plywood. I hope that when mounting calligraphy and painting and cross stitch, we should choose the material of the plate to avoid spending money to reinstall it twice in a few years!