A crease pattern is an origami diagram that consists of all or most of the creases in the final model, rendered into one image. This is useful for diagramming complex and super-complex models, where the model is often not simple enough to diagram efficiently.
The use of crease patterns originated with designers such as Neal Elias, who used them to record how their models were made. This allowed the more prolific designers to keep track of all their models, and soon crease patterns began to be used as a means for communication of ideas between designers. After a few years of this sort of use, designers such as Robert J. Lang, Meguro Toshiyuki, Jun Maekawa and Peter Engel began to design using crease patterns. This allowed them to create with increasing levels of complexity, and the art of origami reached unprecedented levels of realism. Now most higher-level models are accompanied by crease patterns.