Update I'm adding another version.  It's basically the same thing except it's meant to be printed with either dual extruders or an MMU system and I added some dividers inside and changed the magnets to round magnets (6x3mm) which are stronger than the rectangular ones.

Another dice storage box I have created.  This is meant to resemble a book with the top held down with (16) 3x8x1 mini magnets, (8) on the underside of the top cover and (8) in the walls of the box.

Printed with standard PLA at standard Prusa Slicer PLA settings at 0.2 mm layer height.  The dragon images on the cover were a filament color change at the top layer of the book cover.