I have accumulated about two dozen small part boxes with various component assortments (from AliExpress).  It was a nuisance to sort through them when I stored them loose in a drawer.  I designed this simple shelf assembly (using OnShape) to organize them better.

The assembly consists of two of the “BoxShelf” parts, connected by two or four of the "BoxShelf_Connector" parts.

The “BoxShelf_Joiner” part can be used to connect multiple shelf assemblies together.

I included two versions: BoxShelf holds 12 boxes, Box_Shelf_6 holds 6 boxes.

Reorient the BoxShelf_Connector and BoxShelf_Joiner parts flat to the print surface for printing.

Everything printed fine without supports.