Core77

The Strange Attractor, a blog of "strange and exceptional art from all over the world," has produced a collaborative project with several of their contributing authors, entitled Pattern & Shape.

Each contributor designed a pattern for a t-shirt, incorporating a specific geometric shape. The shapes included the astroid, hexagon, isosceles trapezoid (pictured below), parallelogram, arbelos, salinon, square and lozenge.

The patterns turned out awesomely—images of the full line follow, and you can buy them at the site for $23.