Low-fired ware, usually still porous after firing must be sealed with vitreous glaze to be functional.

Natural low-fire secondary clay fluxed with iron, fires porous. Often called "common" clay, found almost everywhere, matures below 2000°F. 

Formation of crystalline deposits on surface of clay or concrete as soluble compounds migrate to surface during drying. See Egyptian paste.

A self-glazing clay body in which soluble alkaline fluxes effloresce to the surface as the piece dries, and subsequently form a thin glassy coating in the firing. 

Any of a group of slightly over 100 substances on earth that may exist as individual atoms, and from which all materials on earth are composed. See periodic table of the elements. In electric kilns, the heating coils. 

Very low temperature (cone 018) glaze colors applied over a previously fired higher-temperature glaze. Allow greater detail, brighter colors than other ceramic glaze effects, but are vulnerable to surface abrasion.

Colored slips formulated to have low drying shrinkage, allowing application to bone-dry or bisque-fired surface before glazing. Commercial under glazes are available in a wide palette of colors primarily for low-fire, but many will survive high-fire.

Primary air drawn into an atmospheric burner, or mechanically injected into a power burner. 

A kiln in which the firing platform is stationary, but the body of the kiln rolls out of the way horizontally on tracks. Often equipped with two firing platforms to be fired alternately.

Al₂O₃—2SiO₂ used in place of regular kaolin to adjust raw fit (reduce glaze drying-shrinkage) in glazes and engobes.

Al₂O₃—2SiO₂—2H₂O pure white kaolin, less plastic than Tile-6 kaolin, frequently used in glazes. 

MgSO₄ water soluble, rarely used as magnesium source in glazes. Most often used as flocculant for slips and glazes. Often added to porcelain and porcelaineous stoneware bodies (1/2 of 1% of dry materials weight) to counteract deflocculating alkalinity released by kaolins or fluxes.

The science of comfortable and effective utility, determining how well a functional object or device works with the human body.

Chemical phenomenon where two materials in combination melt at lower temperature than either material by itself. For example, lithium carbonate and silica each melt at cone 32 (3100°F) but mixture of 55% silica and 45% lithium develops a eutectic and melts at cone 06 1830°. 

Machine that forces plastic clay through a die to produce extruded clay shapes.