A 7 sided dice tray with pockets for dice to sit in. This will fit at least 3 polysets, with 3 or 4 dice in each pocket depending on which die. Use adhesive backed felt for the linings.
The base has circular grooves to make part removal after printing easier. I printed with 0.2 layer height, 4 perimeters, and 4 layers at top and bottom surfaces.