Remember my drawing geometric whirls tutorial? The whirls will work with any polygon shape, but because squares and triangles tessellate so neatly, I made a triangle and a square whirl.
Then I created tessellations out them, reversing the colors for a checkerboard type effect. The resulting patterns were just so neat! Even though they are made out of straight lines, the curving effect of the whirls became a lot more interesting in the tessellations.
See? It makes me dizzy to look at them. But they turned out so nifty that I wanted to show them, I think I'll get fabric from Spoonflower in one of the prints that can be colored in using permanent markers for fun, then make a purse which I can carry markers in for when I get bored waiting somewhere.