Temper (pottery)
Prevents shrinkage and cracking of clay From Wikipedia, the free encyclopedia
A temper is a non-plastic material added to clay to prevent shrinkage and cracking during drying and firing of vessels made from the clay.[1] Tempers may include:
- Bone;[2]
- Chaff;[2]
- Charcoal;[3]
- Ground schist;[4]
- Wood ash;[5]
- Grit;[1]
- Sand or crushed sandstone;[6]
- Crushed limestone;[7]
- Crushed igneous rocks, such as volcanic rock, feldspar, or mica;[5][8][9]
- Grog;[6]
- Plant fiber;[10]
- Horse manure (dried and sifted);[11]
- Crushed mollusc shells (including fossilized)[1][7] (see Shell tempering in the Mississippian culture); and
- Freshwater sponge spicules.[5][12][13]
Some clays used to make pottery do not require the addition of tempers. Pure kaolin clay does not require tempering.[6] Some clays are self-tempered, that is, naturally contain enough mica, sand, or sponge spicules that they do not require additional tempering.[14][13]
See also
Citations
References
External links
Wikiwand - on
Seamless Wikipedia browsing. On steroids.