Modular origami

Each unit is usually quick to fold and has pockets and tabs. Tabs slide into the pockets of neighboring units, and the friction holds the structure together. The Sonobe unit, which assembles into cubes and other polyhedra, is a well-known starting point, and the traditional Japanese kusudama, a decorative ball made from many folded pieces, is closely related.

Consistency matters more than speed: if units differ slightly in size or crease position, the assembly strains and pops apart. Fold all units from paper of the same size and thickness, crease them identically, and assemble on a table. Small 7.5 cm squares are popular because models often need a dozen to thirty or more units.