When a droplet of a dilute solution of a polymer is allowed to evaporate on
a horizontal substrate, the polymer is deposited on the substrate as a reg
ular 2 dimensional pattern of micrometer-sized polymer droplets or lines. I
t was found that the mechanism of the pattern formation involves a Benard c
onvection in the polymer solution and a regularly spaced fingering instabil
ity at the contact line of the solution with the substrate. By using liquid
crystalline polymers, a novel hierarchic pattern can be observed.