1. A defect in coated paper, caused by the separation of the coating layer on the formation of fissures in the surface of the coating due to printing or other converting process. 2. Crack at fold: Fissures in the crease when any paper is folded along a fold line. May be due to separation of coating or separation of fibers. More prevalent when the paper has been over-dried. In boards it may occur along score-folds even though the scoring has been done to minimize cracking at the fold. The term is also applied when coatings crack without fiber failure during a folding operation.