I needed a gift box for one of the big 20-sided dice I made last year, and this is the result.
I have seen images and videos of flat boxes with an integrated lattice-cut conforming piece different places for awhile, and always thought it would be fun to play with. @deirdrebeththoughtfully recreated the lattice pattern, making it easier to design this. I made a simple cube box with top and bottom inserts with the cut lattice. The die sits snugly between them and doesn’t budge even with vigorous shaking of the closed box. Hatch-filled Celtic knots on the box faces, of course.