In high school, we used to use these compressed wood boards for our sand art--they weren't actually pieces of wood, they were sort of particle board/compressed wood/not really sure what to call them. They were hard and smooth, and we glued sand onto them (not looking for the kind you scratch a design into). They were about 9"X12", if I had to guess. Looking for them for a different project, and can't seem to hit anything on Google. Thanks!