Creative Glazes, Your online source for Duncan, Mayco and Gare ceramic glazes

* Home

* Directory

* Ceramics 101
* Which Paint?

Using Glazes

How to Use a Viscosity Cup

How to Pour a Mold


Cleaning Greenware

Color Wheel - How to choose a color

Painting Bisque

How to use Dipping Glaze

Mold Information

The Red-Green Dilemma

Using Specialty Products

Semantics in Ceramics



* Links

* Contact Us

Powered by Creative Cart


*   Creative Glazes  *

white * * * * *

Ceramics 101

Glossary of Ceramic Terms

Alumina ~ An extremely hard mineral which is added to glazes to harden them. The addition of this mineral helps to prevent excessive running of glazes on the surface of the clay during firing.

Banding wheel ~ A revolving stand used to slowly turn the ceramic piece while applying glazes or decorations.

Bisque firing ~ A preliminary firing of greenware which removes all moisture from the piece and provides a more stable form to which glazes and paints are applied.

Ceramics ~ The art of making objects out of clay derived from the Greek word "keramos" which indiated a large Athenian depository of clay.

Cone ~ Elongated, three sided pyramids specially formulated to bend at a specific temperature giving an accurate measurement of the temperature inside your kiln. Visit the Orton Foundation Web Site for more information.

Crawling ~ A glaze flaw which is characterized by the glaze peeling off the surface of the ware or pulling back to leave an area of bare bisque.

Crazing ~ A glaze flaw that resembles a spider's web of cracks over the surface of the ware.

Deflocculant ~ A material such as sodium silicate or sodium carbonate which reduces the amount of water needed to make slip fluid - consequently reducing shrinkage after it is applied to the clay.

Dryfoot ~ Leaving the bottom of a ceramic piece unglazed so that it can be fired standing on the kiln shelf without being stilted. Some molds are specifically designed to produce ware that can be dryfooted. Stoneware and porcelain are always dry footed.

Earthenware ~ A low-fire blend of clay, usually red and porous, used worldwide for domestic ware.

Engobe ~ A colored decorating slip, often opaque. Concentrated color is added to liquid slip and then applied to greenware before firing. Many underglazes are Engobes.

Fettling ~ Trimming the spare clay from the mold pour area before removing the greenware piece from the mold.

Glaze ~ A substance composed primarily of silica which creates a glassy coating that is fused onto the surface of the clay when fired. Glazes may be matte or glossy, depending on their chemical makeup.

Greenware ~ Any unfired clay object.

High-fire ~ The range of firing from cone 2 up to cone 10 or 13. Ware fired at cone 2 and up is usually referred to as Stoneware.

Low-fire ~ The range of firing ware that is usually between cone 015 and cone 1. Ware fired at low temperatures is usually referred to as Earthenware.

Majolica ~ (Maiolica) An earthenware technique made popular in Italy after being introduced by the Spanish. Majolica is created by applying an opaque satin glaze to bisque, then colors are painted on this and fired to fuse the two together and create a bright, colorful surface.

Maturation Point ~ The firing point at which a clay body reaches its maximum hardness and non-porosity.

Mold ~ A plaster form which is used to shape and model liquid clay (slip). The plaster absorbs water from the slip leaving a coating of clay next to the mold surface which takes the shape of the mold.

Opaque ~ Solid color, not transparent in any way. (You cannot see through an opaque color!)

Overglaze enamels and China paints ~ Colored paint-like surface decorations which are applied on top of a previously fired glazed piece which is then fired again at low temperatures, sometimes this takes many applications and firings to complete.

Oxidation firing ~ A firing process which takes place in an atmosphere of ample oxygen in a kiln to produce complete combustion of the contents. This allows the metals in clays and glazes to produce their oxide colors. Bright, clear low-fire colors are associated with glazes and clays fired in an oxidation atmosphere.

Pinholes ~ A small pore in a glaze surface which is caused by escaping glazes.

Plasticity ~ The ability of damp clay to readily change shape without cracking.

Porcelain ~ A blend of clay, usually white, which is fired to a high temperature at which the clay body vitiries and becomes translucent.

Reduction firing ~ A firing process that reduces the proportion of gas to oxygen, forcing the oxygen-starved flame to attack the oxides in the clay and glazes of the ware. Color changes during the process because there isn't sufficient oxygen in the kiln for complete combustion and carbon dioxide in the kiln combines with the oxygen in the clay body and glaze.

Sgraffito ~ A method of producing a design on ceramics, murals, etc. by incising the outer coating of slip or glaze to reveal the ground of a different color. A surface decoration drawing technique in which coats of contrasting underglazes or colored slips are applied to clay, then scratched off with a fine-pointed tool to reveal layers beneath the surface.

Slip ~ A finely sieved mixture of clay and water, either white or colored, which can be applied to clay surfaces in one or more layers. Slip is also poured into molds to cast ceramic pieces.

Slip Trailing ~ A method of decorating ware by squeezing slip from a bottle or nozzle onto the surface of the pottery to create raised lines.

Spare ~ The portion of clay waste which is trimmed from the mold before the greenware is removed from the mold.

Stoneware ~ A blend of clays, usually brownish in color, which is characteristically fired to a high temperature at which the clay body becomes vitrified and non-porous, but not translucent.

Terra sigillata ~ A variety of slip made by mixing clay and water and allowing it to settle. Characteristically thinner than other slips, terra sig dries to a soft, silky sheen.

Terra cotta ~ A type of clay whose name translates as 'baked earth'.

Transparent ~ See through color. Transparent glazes generally 'settle' into detailed areas, making them darker and bringing the detail to view.

Underglazes ~ Colored agents, such as slips and commercial underglazes, which are used under a glaze. Most commonly indicates colors used to decorate greenware and bisque before a protective clear glaze is applied.

Vitrification ~ The point at which a clay body or glaze reaches a glassy, dense, hard and non-absorbent condition.

Wax resist ~ A wax emulsion especially created to repel underglazes and glazes applied over them. Apply one good coat of Wax Resist over the glaze and allow it to dry thoroughly before proceeding with your technique. Fire your glazed piece to Cone 06. The wax is burned off during firing, revealing the designs you protected from other paints applied around them.

General Paint Descriptions - Ceramics 101

Simple, Secure, Convenient - Creative Glazes.

white * * * * *
Copyright 2000-2016, Creative Connections, Inc.
Creative Glazes is a trademark of Creative Connections, Inc.