Woven Slit Module (WSM) is an origami unit which can be used to build different kinds of modular assemblies, from simple cubes to more complex objects. They can weave with other units to form interesting patterns. In some models, these units can slide along one another to produce action origami — assemblies which can be transformed into different shapes without taking the units apart. WSM can be made from rectangular paper of different proportions with broad units being useful for models with densely packed and ornamented walls and thin skinny units being useful for lattice-like models. A paper aspect ratio of 2:1 is a good starting point for many models.
This unit is based on some folded draft units I found during a routine clean-up of my origami stuff. Apparently I had the general idea already a few years ago, but the design lacked polish and clearly I was in the dark about how to connect the units into any interesting shape. WSM bears some resemblance to the Hacky Sack Unit designed by Winston Chan.