Patterns I've noticed

Greek key

image source: http://www.clker.com/clipart-edge-to-edge-4-turns-greek-key-inverse-meandre-with-lines-1.html

Damask

image source: http://www.clker.com/clipart-damask-pattern.html

Chevron

image source: http://www.clker.com/clipart-6700.html

Charlie Brown shirt

image source: http://www.peanuts.com/characters/charlie-brown/#.VLbybdLF9PY