ceramics vocab quiz

BISQUE

Pottery that has been fired to a low temperature, usually cone 05 (1900°F), but not yet glazed.

CERAMICS

Clay products made permanent by heat. The word comes from the Greek "keramos" meaning potters clay and the ware made from it.

FIRING

The process by which clay converts to ceramic. It involves a heat of at least 1100° F. During the firing clay is changed to a stone-like material and organic matter is burned away. The colors of the minerals change, and a layer of glass known as glaze can be fused to the surface of the ware

GLAZE

A liquid suspension of finely ground materials which is applied by brushing, pouring or spraying on the surface of bisque-fired ceramic ware. After drying, the ware is fired to the temperature at which the glaze ingredients melt together to form a glassy surface.

GLAZE FIRE

A firing cycle to the temperature at which the glaze materials melt.

Gloss Glaze

A shiny surface glaze.

GREENWARE

Dry, unfired ceramic ware.

GROG

Ground up fired clay. Grog provides texture, opens up the clay body to help uniform the drying, and cuts down on shrinkage in clay bodies

KILN

A furnace for firing pottery.

KILN WASH

A coating that protects kiln shelves from runny glazes.

PLASTICITY

The ability of clay to bend without breaking and to hold a chosen form.

LEATHER HARD

Clay that has dried sufficiently to be stiff, but is still damp enough to be joined to other pieces of clay with slip; ideal for trimming pots or carving.

MATTE GLAZES

A glaze that is dull-surfaced.

OXIDATION

Firing method in which an excess of oxygen is available, permitting specific chemical reactions to take place that affect the appearance of the glaze. Usually performed in an electric kiln.

REDUCTION

A glaze firing in which oxygen is limited (reduced) to enhance the properties of the clay body and affect the appearance of specific glazes.

SCORING

The process of scratching the facing surfaces of clay joints when attaching clay parts to one another. After scoring, the scratched areas are coated with slip and then pressed together, which creates a stronger, bonded joint.

SLIP

Clay and water mixed together to a soupy consistency.

UNDERGLAZE DECORATION

A ceramic decoration applied to greenware or bisqued surfaces. Pieces are then covered with glaze to make them shiny after firing.