A “Boxel” is a 12-sided, corrugated cardboard building block with rhombus-shaped (diamond) sides, of my own design. Each block is made of twelve mechanically cut and folded panels which can be assembled without additional hardware or glue. The underlying geometrical shape of a Boxel is called a rhombic dodecahedron.

Boxels of the same size can pack together and tile infinitely. Boxels of any size can be connected, though not if they are connected to the same differently-sized block.