"A Penrose tiling is a non-periodic tiling generated by an aperiodic set of prototiles. Penrose tilings are named after mathematician and physicist Roger Penrose who investigated these sets in the 1970s. The aperiodicity of the Penrose prototiles implies that a shifted copy of a Penrose tiling will never match the original"

http://en.wikipedia.org/wiki/Penrose_tiling

My penrose tiles are simple: a "fat rhombus" and a "thin rhombus". Print as many of each as you need to make patterns!

Can be printed flat or on edge.