aclift: /* Crazing */

===Crazing===
Crazing appears in the glazed surface of fired ware as a network of fine hairline cracks.. This can be seen as an aesthetic flaw, and in the case of functional pottery it is a sanitary concern because these cracks, although microscopic in width, can potentially harbour bacteria. Some glazes are intentionally formulated to cause this flaw for its aesthetic qualities. These are known as crackle glazes. Such effects are popular for glazes on [[Raku]].

Crazing is caused by the glaze being under too much tension.
The tension occurs when the glaze contracts more than the body during cooling in cases where the glaze material has a higher [[coefficient of thermal expansion]] than the body.

[[category:Clay Terminology]]
[[category:Glaze defects]]


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