It's all polymer clay (Fimo). :) The stripes are made by alternating flat layers of black and white clay and then "slicing" the layers to make a flat stripey slice (does that make sense?). The checkers are just 1 additional step--you put the black and white sheets on top of each other, and then slice the layers into even columns and turn every other column upside down (and then you do the "making the flat slice" thing). :) And the zebra-type effect was really just marbing black and white together and running it through the pasta machine. Heehee.
Oh yeah, and I cut the shapes out. Fimo is cool 'cause (among other reasons) if I want to put a gemstone in, I can just stick it right in the middle of the piece I'm making before it's baked, and then it bakes at a low temperature and voila! Gemstone jewelry. Too much fun.