A defect of gravure printing characterized by small rings of color (typically visible under magnification), caused by solvent trapped beneath a dry ink film. As the solvent is vaporized, it bursts through the surface of the ink, forming "craters" (also called volcanoes). Using a slower-drying ink or reducing the heat of a drying oven (if the ink is a heatset ink) are ways of alleviating the problem.
'Cratering also refers to a defect of screen printing in which depressions form in a printed ink film which may be deep enough to expose the substrate.