There are four rules that any flat-foldable crease pattern must obey.

Though most origami models are three dimensional,their crease patterns are usually designed to fold flat without introducing any new creases or cutting the paper.The mathematical rules behind flat-foldable crease patterns are much simpler than those behind 3D crease patterns—it’s easier to create an abstract 2D design and then shape it into a 3D form.There are four rules that any flat-foldable crease pattern must obey.