Bought these frames hoping they would be strong enough to hold jigsaw puzzles.  Risked buying three and they really do the job.  Reviews said the magnets are super strong, and they are! Also, when you want to change puzzles it takes two seconds.  You don’t need the bottom slats because the puzzle is stiff (taped it all over the back).  You can use the bottom slat for another puzzle by affixing string to it, making it a top slat, doubling its function.  Easy.  Perfect solution.