A defect in a lacquer or dope finish caused by moisture condensing on the surface before the finish dries.

If the humidity of the air is high, the evaporation of the solvents cools the air enough to cause the moisture to condense. The water condensed from the air mixes with the lacquer or dope and forms a dull, porous, chalky-looking finish. This is called blush. A blushed finish is neither attractive nor protective.