A scheme for describing this kind of degradation is suggested. Laminal disruption is a defect of a film, a thin cutting, or a coating which is an integral part of an artifact-paint, lacquer, marquetry, and enamel are examples. Disruption may lie parallel to the surface plane or contour: cleavage; it may run perpendicular to the surface: fissurage. Cleavage takes one of two general forms-shell clefts and ridge clefts. Fissurage also follows one of two types-rifts and crevices. The varied patterns that occur within these types can be described by terms that relate to the facts of their appearance.