4.1 Break depends on the fiber structure and on the relation between the grain and other strata of the leather. A fine break, or a grain pattern which shows many fine wrinkles when it is bent to form a concave surface, as it is in the vamp of a shoe, reflects favorably upon appearance and serviceability. A coarse break, on the other hand, where a few coarse wrinkles are formed on bending the grain to form a concave surface may indicate that the grain layer is separating from the corium or main stratum as in pipey leather. Shoes made from fine-break leather are more attractive and tend to wear longer than shoes made from coarse-break leather. (See MIL-STD 663 and the ALCA Journal).⁴