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| Widely occurring aluminum silicate mineral resulting from natural decomposition of feldspar and granite. |
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| Clay mixture formulated of clays and other ceramic raw materials to give desired working characteristics. |
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| Low-Fired ware, usually still porous after firing- must be sealed with vitreous glaze to be functional. |
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| Low temperature, porous earthenware claybody, fires red-brown due to high iron content that also fluxes clay, making it the most durable low-fired clay after firing. |
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| Low-temperature white claybody. |
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| High-fired vitreous ware. literally as hard and durable as stone. Matures from 2200-2400 degrees F. (Cone 5-11) |
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| High fired vitreous claybody containing kaolin, silica, fluxes, and often ball clay to increase plasticity, with total clay component not more than 50%. Usually pure white of "eggshell" in color, some porcelains may fire translucent where thin. |
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| Any dry, unfired clay form |
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| Condiditon of clay where it has stiffened but is still damp. Point at which pieces are joined and most surface modification and trimming are done. Soft-leather-hard ideal for forming, joining, thick slip-decorating. Medium-leather-hard good for thin slip-decorating, joining, incising, carving, piercing, Hard-leather-hard good for thin slip-decorating, carving, scraping. |
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Definition
| At the leather-hard stage, removal of excess clay from a piece, using any of a variety of sharp cutting tools. |
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| Completely dry (and very brittle) state clay must reach before firing. |
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| Colored slips formulated to have low drying shrinkage, allowing application to bone-dry or bisque-fired surface before glazing. Commercial underglazes are available in a wide palette of colors primarily for low-fire, but many will survive high-fire. |
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