1. Apparatus for implementing non-destructive quality control of substrates for receiving microarray features of biological microarrays and for non-destructive quality control of microarrays comprising: a microarray substrate including a substrate surface carrying a plurality of microarray elements; a thermally insulated chamber receiving said microarray substrate; said thermally insulated chamber having an inlet port and an exhaust port; a source of moist warm air having a temperature greater than room temperature, and the moist warm air having a dew point higher than the temperature of the substrate and a carrier gas being applied to said inlet port and transporting said moist warm air to said exhaust port creating a layer of condensate droplets of a chemically inert water-soluble liquid on said surface of said microarray substrate under inspection; said condensate droplets being densely spaced droplets having an average size substantially less than the microarray features; said layer of condensate droplets affecting both transmission and scattering of light on the surface; and a digital image processing system illuminating said surface of said substrate under inspection; detecting an image of said illuminated surface of said substrate under inspection; and identifying a pattern of said condensate droplets on said surface of said substrate under inspection, said pattern characterized by spatial distribution, average size of the condensate droplets and spacing between the condensate droplets, reflecting variation in wetting properties of the substrate; said digital image processing system visually detecting an area indicating presence of undesirable variation of wettability and rejecting said substrate under inspection, responsive to detecting the area indicating presence of undesirable variation of wettability.