Glossary

Bisque (bisqueware):  a piece of unglazed clay, pottery or sculpture, that has been bisque fired to Cone 010 - 04

Bisque Firing:  typically, the first firing of clay artwork without a glaze to Cone 010 - 04, around 1800° Fahrenheit.

Bone dry:  unfired clay which is warm (not cool or damp), dry, and dusty/chalky in feel. Ceramic ware needs to be this stage prior to bisque firing whereby the physical (free) water has evaporated.

Clay: a decomposed granite-type rock that may be used for making object for functional and sculptural purposes. In its theoretically pure state, it consists of alumina, silica, and water.

Coiling: To construct pottery or sculpture by rolling out clay in thin ropes to build a form

Earthenware: Clay bodies fired at temperatures below cone 1 (2110° F) that remain somewhat porous and open in structure. The vast majority of the world's pottery has been this type because of the wide prevalence of the clays and the relative ease of reaching the kiln temperature necessary to mature the claybody. Two examples are terra cotta and whiteware (the type of clay we are using at Lincoln).

Functional: describes an object that will be used for some activity, usually refers to physical activity. An object to be used and not as an object of contemplation.

Glaze: a thin layer of glass fused to the surface of fired clay. Glaze can be smooth or textured, shiny or dull finished, and may be colored by a variety of oxides/carbonates. The raw unfired glaze never looks like what it will look like fired.

Glaze firing: typically the second and final firing of a clay artwork that has been bisque fired, which usually includes the coating of a raw glaze. Once fired the glaze will be fused to the clay. 

Greenware: refers to any state of raw/unfired clay. Including wet, leatherhard, and dry/bone dry.

Handbuilding: forming clay shapes by hand (without a wheel) by pinching, coiling, slabbing, molding, or combinations of these techniques.

Kiln: an insulated fireproof box, usually brick lined oven into which heat is introduced by combustion (fuel fired) or by radiant energy (usually electric) designed for firing ceramic ware. Kilns come in a wide range of shapes and sizes, some permanent and some portable.

Kiln Wash: a thin coating of refractory material (usually alumina and kaolin) applied to kiln shelves, the bottoms of kilns, and other "hot face" surfaces to protect them from glaze drippings and to reflect heat.

Leatherhard: a stage in the drying process of clay when it becomes stiff but still flexible, but is still damp enough to be joined to other pieces. The name is akin to the description of shoe leather and clay at this stage may also be carved, incised, engraved, planed, and trimmed/turned. It can also be said that its consistency is similar to hard cheese.

Matte: not shiny 

Pinch pots: small vessels made by manipulating clay by hand. The first type of pottery ever created. 

Press Mold: a form which clay is compressed into, resulting in a repeatable shape or texture. These are usually made of plaster. We used plastic as well as found objects lined with plastic or newspaper. 

Reclaimed/recycled clay: unfired clay can be re-used by watering down, remixing, allow to firm up and finally re-wedged.

Resist technique: A decoration method where a substance such as wax, newspaper, tape or many other things are applied to a clay surface to keep glazes and slips from adhering.

Rib: a tool for smoothing and shaping surface contours of clay. 

Scoring: making scratches, usually in a cross-hatch pattern, with a knife, needle or serrated tool and using slip, to help make two pieces (coils, slabs, handles, etc.) of clay adhere to each other.

Sgraffito: a technique where clay is coated with a colored slip which is carved through to expose the clay. This is another word for scratching into the clay to make a pattern or design. 

Shrinkage: the progressive lessening or contraction of clay in measureable dimensions and volume during both drying and firing. Different types of clay shrink at different rates, usually ranging from 6-14%. At Lincoln, our clay reduces in size by 12%. 

Slab (slabbing): The process when clay is rolled into flat sheets and made into pottery or sculpture.  

Slip: clay that is mixed with enough water to be as fluid as cream or as thick as yogurt. Uncolored slip is used to attach together unfired and moist clay pieces to create functional and non-functional art. 

Slip Trailing: colored slip or glaze squeezed from container in thin lines onto clay or bisque.

Slump Mold: a rounded form used with clay to create a shape in that form.

Underglaze: usually refers to pigments, applied to raw or bisqued clay, that are normally covered with a glaze, such as commercial liquid underglazes like AMACO, chalks/crayons, and pencils. 

Wax/wax resist:  It is a liquid substance painted or dipped on ceramic art to resist water based liquids such as glazes, slips or stains. It is often applied to the entire bottom of ceramic art to help keep glaze from the bottom before firing. 

Wedging: a process by hand where clay is mixed, cut & slammed, and "kneaded" to eliminate air pockets, made smoother, denser and homogenous.