- Bat
- A removable disk that fits on the wheel head, so you can lift a freshly thrown pot off without touching it.
- Bisque
- The first firing, and the hard but porous pottery it produces. Also called bisqueware.
- Bone dry
- Clay that has lost all the water it can lose in air. Pale, light and very fragile. See drying.
- Centering
- Getting clay to spin evenly around the middle of the wheel before shaping. See wheel throwing.
- Clay body
- A prepared blend of clays and minerals made to work and fire in a certain way. See clay bodies.
- Coil
- A rope of clay used to build up a wall by hand.
- Cone
- A small ceramic pyramid that bends after a set amount of heat work. Also the name for a firing range, such as cone 6. See firing.
- Crazing
- A fine web of cracks in a fired glaze, caused by the glaze shrinking more than the clay.
- Earthenware
- Low-fired clay that stays slightly porous. Often red or buff.
- Flux
- An ingredient that helps glaze or clay melt at a lower temperature.
- Foot
- The base of a pot, often trimmed into a ring and left unglazed.
- Greenware
- Any unfired clay object, from wet to bone dry.
- Grog
- Fired clay crushed into grains and added to a clay body for strength and texture.
- Kiln wash
- A coating painted on kiln shelves so drips of glaze can be chipped off.
- Leather hard
- Partly dry clay that is firm enough to hold its shape but can still be carved and trimmed.
- Oxidation
- Firing with plenty of oxygen in the kiln, as in most electric kilns.
- Plastic
- Clay that is soft and workable, able to bend without cracking.
- Porcelain
- A fine white clay body, mostly kaolin, fired to a hard, dense finish.
- Reclaim
- Unfired scrap clay soaked and dried back to a workable state.
- Reduction
- Firing with limited oxygen, usually in a gas kiln, which changes how many glazes look.
- Rib
- A flat hand tool of wood, metal or rubber used to shape and smooth clay.
- Score
- To scratch rough lines into clay surfaces before joining them.
- Slab
- A flat sheet of rolled clay. See hand building.
- Slip
- Liquid clay used as glue for joins or as a decorative coating.
- Stoneware
- Clay fired at mid or high temperatures to a dense, strong body.
- Thermal shock
- Cracking caused by heating or cooling one part of a pot much faster than another. See care.
- Throwing
- Shaping clay on a spinning potter's wheel.
- Trimming
- Carving away extra clay from a leather-hard pot, usually to form a foot.
- Underglaze
- Colored, clay-based paint that stays put in the kiln, often covered with clear glaze.
- Vitrification
- The point at which clay particles fuse and the body becomes dense and close to watertight.
- Wedging
- Kneading clay to even out its moisture and remove air pockets.
- Witness cone
- A cone placed where it can be seen through the peephole, to check the heat work of a firing.
Where these words come up
The guides use these terms in context. Start with clay bodies for materials, hand building and wheel throwing for shaping, the drying and firing guides for the kiln side, and glazes for surfaces. The getting started page covers classes and studios.