This is a road-side stand in Mexico in 2016. Each of these "cazuelas" (casseroles) have a flame under them to keep the food inside warm. The pedestal is unglazed. The ware is thick and heavy. The casseroles are hand decorated with under glaze slip colors and a very thin layer of lead glaze is painted over (producing a terra sigilatta type appearance, but with brush stoke texture). These have been made and used here for hundreds years. How can they not crack over an open flame? The flame is small. The clay is fired as low or lower than potters in Canada or the US would even fired their bisque. It is porous, open and able to absorb the stresses. They know these pieces are not strong, so they treat them with care.
Glossary |
Ovenware
Ovenware clay bodies have a low expansion by virtue of materials in their recipe and/or the way they are fired. But potters bend the rules. |
---|---|
Glossary |
Flameware
Flameware is ceramic that can withstand sudden temperature changes without cracking. The low thermal expansion of true flameware makes craze-free glazes very difficult. |
Glossary |
Terra Sigilatta
Terra Sigilatta is a sedimentation process used by potters to remove coarse particles from a clay powder. It enables burnishing and gloss surfaces without the use of glaze. |
Glossary |
Terra cotta
The term Terra Cotta can refer to a process or a kind of clay. Terra cotta clays are high in iron and available almost everywhere. While they vitrify at low temperatures, they are typically fired much lower than that and covered with colorful glazes. |
Sign up at the home page.