A rich spectrum of crystal patterns are observed when a drop ofionic or protein solution evaporates on a solid substrate. Other thanthe well-known crystal fingers from homogeneous crystallization,heterogeneous crystallization at the contact line produces stripe andfractal patterns at much smaller length scales between 20 and 200microns. Such patterns are shown to result from interplay amongcrystallization, contact-line motion, non-uniform evaporation anddiffusion within the precursor films of wetting drops. Universalcorrelations among pattern length scale, bulk concentration andcrystal size are established and explained theoretically.Heterogeneous crystallization is also shown to modify thecontact-line dynamics to produce macroscopic stain topologies likecircles, bands, crescents, stars etc.