Glossary

Bisque  Clay that has been fired once, but remains unglazed.
Body  1) The particular ingredients that comprise the substance of which a ceramic object is made and which determines whether the ceramic is china, earthenware, or stoneware. 2) The main part of a ceramic object.
Bone China  China that is translucent and is composed of bone ash added to clay to provide a whiter and stronger body.
Casual China   An informal, vitrified ware that is generally less expensive and more durable.
Ceramic  Any article made of fired or baked clay.
China  Ceramic ware that is finer and less porous than earthenware.
Chip  An avulsion of the ceramic body. The size may range from very large to almost so tiny as to be inconspicuous.
Clay  A naturally occurring substance that varies in composition. It is moldable when wet and dries to a rigid structure.
Coupe  The most widely used mid-century modern plate shape, consisting of a flat surface that curves up at the edges. A purely coupe-shaped plate has no outer rim.
Craze or Crazing   Minute cracks in the finish or glaze which is caused by when the ceramic body and glaze have different coefficients of expansion. If either the body or glaze contracts faster than the other, minute cracks may occur in which dirt may become trapped. Crazing is considered a defect in mid-century modern dinnerware, often significantly affecting its value.
Crockery  A term once used to generally group earthenware together.
Decalcomania  Decal. The printed decoration that is applied to a ceramic object, either over or under the glaze, as a means of decoration.
Earthenware  A more porous and less durable ceramic object that is generally fired at a lower temperature than china and porcelain.
Delft  1) Generally a brown pottery that is covered in a white glaze and decorated in blue which originated in Delft, Holland. 2) A ceramic object which looks like Delft (blue Dutch-like decoration on white).
Embossed  The raised decoration actually made from the ceramic body. Intaglio is a depressed decoration in the ceramic body.
Engobe  Liquid clay or slip that is either colored or white that is applied before the clear glaze. When the engobe completely covers the object, it changes the color of the object completely. In some cases, decorations were incised into the engobe revealing the underlying color of the body in contrast to the overlying engobe coloration.
Feldspar  An ingredient found in crystalline rocks that when mixed with clay adds translucency.
Firing  The heating or baking of ceramic ware in a kiln that permits clay to dry and harden into a rigid body. Firing may be done for an object, its decoration, and glaze all at once, or in several stages. Bisque firing, glaze firing, and metal (such as gold or platinum) firing.
Glaze  Glazes are a clear coating of a crystalline type substance that when applied to a ceramic object, gives it a protective coating. Glaze finishes are often glossy and may be clear, colored, or completely opaque.
Glost Firing   The second heating of a ceramic object in a kiln to harden the glaze on bisque.
Holloware or Hollowware   1) Ceramic objects that are not flat, like the creamer, shakers, teapot, bowls, and covered casseroles. Plates are considered ceramic flatware. 2) The serving dishes as opposed to flatware which are serving utensils.
Intaglio  A design debossed into the surface of the ceramic body.
Kaolin  A fine clay that lends whiteness and strength to the ceramic body and is an important ingredient in china.
Kiln  (Pronounced kill or kiln). An oven for firing clay. Kilns from America's 1800s had fat smoke stacks that resembled a beehive and hence were called beehive kilns. By the 1920s, automation moved ware through kilns in either a tunnel or circular fashion.
Majolica  Earthenware with a red clay body and covered in an opaque, highly colorful glaze decoration.
Mold Marks   1) The seams in ceramic that are generally removed after casting. 2) The inscription in the mold where the backstamp would normally reside.
Backstamp  The marking on the bottom of a ceramic object, often printed in ink or marked by decal, that identifies the manufacturer and/or line.
Overglaze Decoration   Decoration applied to the ceramic object after glaze decoration. Overglaze decoration was phased out in favor of underglaze decoration which protected the decoration under a layer of glaze.
Pin Holes or Pops   Minute holes in the glaze, that interrupt the continuity of the glaze surface. These are considered factory defects.
Pin Marks   The marks on the underside of ware at the points, generally three, where the object was supported during firing. Fine china will generally not show such pin holes as these are removed later.
Pottery  1) Absorbent earthenware that is generally low fired, made of red clay, and easily chipped. 2) Any ware made of clay.
Run of the Kiln   All ware from a kiln except obvious defects.  
Semi-Vitrified  Higher fired ware that nearly approaches the strength and firing temperatures of china which is considered vitrified ware.
Sgraffito  A style of decorative method that is created by scratching through the engobe layer.
Slip  Liquid clay.
Stoneware  A very strong, typically high-fired ware that has low moisture content and has a higher sand content.
Tunnel Kiln   A kiln that moves ware on flat cars through the tunnel during firing.
Underglaze Decoration   A decoration that reside underneath the glaze coating, affording the decoration protection against fading and wear.
Vitreous or Vitrified Body   High fired ware that has a very low moisture content and porosity. Vitreous ware is very strong.