Craquelé is a type of ceramic glaze that is intentionally or unintentionally crazed. The result is a crack pattern caused by thermal expansion mismatch between the body and the glaze. After the glaze solidifies (as the kiln cools) it shrinks more than the body. To relieve the tension of being stretched, it cracks. Crackle glazes are typically found on ware fired at low temperatures. Stains and other colorants are often rubbed into the crack lines to heighten the effect. Chinese wares of the Song (960-1279 AD) and Yuan dynasties (1271-1368 AD) with deliberate crackle glazes are called Guan (官) ware and Ge (哥) ware, they are the first example known with “Craquelé” glaze ever made.