  A study of crack patterns in laponite films of different thickness is
presented. Two cracking regimes are observed. The earlier with a higher rate of
desiccation and shrinking has predominantly four-fold vertices in the crack
network, while the later regime has less volume shrinking and forms mainly
three-fold vertices. The pattern shows a self-similarity under coarse-graining.
The graph of area covered by the cracks versus minimum crack-width resolved,
scales with the film thickness. Curves representing crack area for different
thickness can thus be made to collapse onto a single curve.
