A book-shaped print-in-place box with individual slots for a polyhedral 7-piece dice set. No supports needed. Your choice of physical latches or magnets, and of standard or largish dice. The layout for the larger dice is a bit chaotic, but they fit. The uploaded cover and spine are blank so you can emboss anything that amuses you. If you change the filament partway through you can get different colors of pages and binding.

Author of the design: https://www.thingiverse.com/Cynthia

Design: https://www.thingiverse.com/thing:7086424