Definition

• Ball clay is a fine-grained, highly plastic secondary clay that fires to white or near white.
• Bisque refers to unglazed but fired ware.
• Bisque Fire is the first firing of a clay. This fire eliminates trapped water and carbonaceous materials prior to the glazing process.
• Body refers to a combination of natural clays and non-plastics formulated to possess workability and firing characteristics.
• Bone China is porcelain made of bone ash produced in Japan and England. Bone China is known for its translucent qualities.
• Bone Dry refers to unfired clay that has no moisture other than the natural humidity in its environment.
• Burnishing is the act of rubbing greenware (clay) with any smooth tool to polish it, and tighten the surface.
• Celadon refers to a special greenish glaze. The name is Western, not Asian, yet celadon was never produced outside Asia. Celadon resembles precious jade, both in color and in transparency.
• China is a porcelain clay body, usually translucent. Artists usually fire the clay and glazes together at high temperatures as in the traditional Asian method, or create low-fire porcelain as in the European method
• China is commonly referred to as “whiteware”, sometimes translucent.
• China clay is a rare material found in the United States used in the blending of whiteware and porcelain bodies.
• Clay is an earthly material, finely grained which is formed from the decomposition of igneous rock. When this material is combined with water, it becomes plastic enough to be shaped. When subjected to red heat the material becomes progressively more dense resembling rock
• Clay is a combination of decomposed and altered rock consisting of a variety of hydrated silicates of aluminum and non-plastics, such as quartz, and other organic matter.
• Coiling is a method of forming pottery or sculpture from rolls of clay that are smoothed together to form the sides of a jar or pot.
• Crackle is the decorative and intentional “netting” created on the surface of a glaze due to a variation in the expansion and contraction of both the glaze and the clay body in the kiln.
• Elasticity is the ability of a clay to be manipulated without breakage.
• Firing is heating pottery or sculpture in a kiln or open fire to bring the clay to maturity. The temperature needed to mature the clay varies with the type of body used. Also, heating glazed ware to the necessary point to cause the glaze to mature.
• Glaze is a very thin, transparent colored paint applied over a previously painted surface to alter the appearance and color of the surface.
• Greenware is unfired pottery or sculpture.
• Impressing is the process of decoration in which impressions are stamped into a clay surface.
• Kaolin is a soft white clay, essential for the creation of china and porcelain, named after Kao-Ling (Gaoling) a hill in Jiangxi, China, where it was mined for centuries.
• Kiln is a furnace or oven built of heat-resistant materials for firing pottery, glass, and sculpture.
• Latex Resist is where liquid latex is used to create patterns on ceramics. The latex is painted onto unfired ceramic ware to keep those pattern areas from being covered in slip or glaze.
• Leather-hard is the condition of raw clay when most of the moisture has evaporated, but is still soft enough to be carved or joined to other pieces.
• Low Fired is where clay is fired at a temperature sufficient to fuse it into a solid mass, but too low to make it completely nonabsorbent.
• Majolica glaze is an opaque glaze with a glossy surface, usually white.
• Master mold is the plaster shape from which repeated copies of a mold can be made.
• Mishima refers to decoration carved in leather-hard clay, which is then covered with engobe and ribbed off when drier, leaving engobe inlaid in the carving.
• Once Fire is a slow firing cycle which combines both bisque and glaze firings. Also known as "single fire".
• Opalescent Glaze refers to a glaze with a milky or translucent quality.
• Open Firing is a firing in which the flame touches the piece directly.
• Overglaze is a glaze decoration applied on the surface of a fired, glazed piece.
• Oxidation Fire is a firing during which the kiln chamber retains an ample supply of oxygen.
• Pinch Forming is a method of forming objects by pinching the clay wall.
• Plasticity refers to the quality of clay that allows it to be easily manipulated and still maintain its shape.
• Press Mold is a one-piece mold into which clay is pressed or casting slip is poured.
• Raku is a technique of rapidly firing low-temperature ceramic ware. These were used traditionally in Japan to make bowls for tea ceremonies.
• Ram Pressed is clay pressed into a mold by a machine, allowing multiple reproductions of the same shape.
• Raw is referring to that which is unfired or in a natural state.
• Reduction Fire is a firing in which the supply of oxygen in the kiln is inadequate to promote complete combustion. Carbon monoxide thus formed combines with oxygen in clay and glazes, altering their colors.