Extensive crazing can lower the value of pottery, but small amounts shouldn't affect its price. Although mint pieces always demand the highest prices, some pottery collectors are willing to overlook minor defects.
Crazing seldom decreases the value of pottery if the piece isn't chipped or cracked. Crazing refers to a network of fine cracks that develop in fired glaze that are caused by using the wrong type of glaze for a specific clay, thermal shock, expansion of the clay after firing or overfiring. Crazing isn't necessarily evidence of age. Crackle-glazed pottery doesn't have a glaze defect because crackle glazes are specifically formulated to produce controlled crazing.