Thanks again. Just to be clear, the friction fit comes from sliding the bottom on to the box, the same way that is often used to hold a lid in place . A 3/8” thick piece of Walnut is milled to tightly fit into the body of the box, then glued to the bottom. That way the bottom will slide snugly in place and not fall off. I had originally planned to add small magnets to hold the bottom in place, but I found that they were not necessary. I left a bit of clearance inside for the cardboard box. And you are right, I hope they don’t change the size of the boxes!