I have cut a few hundred puzzles from solid wood, mostly poplar and pine. About a week ago, I had a puzzle to make with some fragile parts that cried out for plywood. I cut it from 3/4-inch Baltic Birch plywood. Not only did it fix the breakage problem, but making the puzzle from Baltic Birch plywood was much easier than with any of the woods I had previously used. The cuts were almost glassy smooth, and very little sanding was required. I am considering making this my go-to material for puzzles.