  We investigate the geometry of two-dimensional polygonal cracking that forms
on the air-exposed surface of dried starch slurries. Two different kinds of
starches, made from potato and corn, exhibited distinguished crack evolution,
and there were contrasting effects of slurry thickness on the probability
distribution of the polygonal cell area. The experimental findings are believed
to result from the difference in the shape and size of starch grains, which
strongly influence the capillary transport of water and tensile stress field
that drives the polygonal cracking.
