Ceramics Vocabulary

APPLIQUE - The application of a clay shape or form scored to the surface.         

BAT - A slab or platform on which clay is handled; a circular device attached to the wheel-head.

BISQUE - Unglazed clay, fired at a low temperature. Clay that has been fired once

BISQUEWARE – is a ceramic piece that has been fired once

BISQUE FIRING - The process of firing unglazed clay to a low temperature to harden the clay and drive the physical water from it. The approximate temperature of this firing is 1815 F.

Blistering- this is caused by gases escaping when a glaze is firing too fast or the coat of glaze is too thick

Body-the main part of a vessel, usually the largest

CENTERING - The act of aligning the clay on the potter's wheel in order to proceed with forming and shaping.

CHAMBER- the area inside the kiln where pottery is placed to be fired 

CERAMICS – Objects made of clay fired sufficiently high in temperature for a chemical change to take place in the clay body, usually over 1550 F

CLAY BODY - A mixture of different types of clays and minerals for a specific ceramic purpose.

COIL CONSTRUCTION - Ropes of clay that are stacked to form a wall. This technique is one of the most commonly used hand-building methods.

CONING- When a mass of clay is worked on a potter‘s wheel, it is coned by repeatedly drawing it up into a conical shape and then flattening it down to center it on the wheel and shape the mass. • The first part of this process is known as coning up, the second as coning down.

CRACKLE GLAZE -  Minute decorative cracks in the glaze that are often accentuated by rubbed – in coloring material

DRY FOOTING – Glaze is removed from the bottom of a piece before firing, making stilting unnecessary.

EARTHENWARE – a  low fire clay. Porous and not waterproof.  Needs to be glazed to be functional

ELEMENTS – Coils of high temperature resistance wire convert electricity to heat

ENGOBE – A white or colored thin layer of clay used to decorate a bisque pot. I t may or may not be glazed over

FIRING – Clay is hardened by heating it to a high temp, fusing the clay particles. Primitive pottery is usually fired on the ground or in pits with whatever flammable material is available. Kilns allow a more efficient use of materials and more control over the atmosphere during a firing. The two basic atmospheres, oxidation and reduction, affect the color of the final piece.

FOOT- the base of the vessel upon which it stands

Foot Pedal-  Device that regulates on speed on the electric potters wheel. • An artist will set the speed with the foot pedal and then remove his/her foot to evenly distribute his/her weight 

GLAZE - A glassy coating that has been melted onto a ceramic surface. Glazes can be colored, opaque, translucent or matte

GLAZE FIRING - Typically the second firing of a piece pottery which has been coated with glass forming materials. The approximate temperature of this firing 2300.

Gravity-  Wet clay is weaker than dry clay and can “Slump” or collapse due to gravity. 

GREENWARE - Unfired pottery that is bone-dry, a state in which clay forms are the most fragile.

High Relief-  In this type of sculpture, the forms project further out from the background, has a greater depth and makes use of larger undercuts that show more form

Hump Mold (also known as a Drape Mold) a convex support mold that holds clay in a certain shape until it hardens

INCISED – These decorations are surface designs cut into the clay. Mishima (inlaid clay) - variation- contrasting colored slip is inlayed into incised lines. This can be done using wax resist – incising then applying slip or slip may be applied to incised lines and sanded off the raised body.

In the Round • A type of sculpture to be viewed from all sides; freestanding. Sculpture surrounded on all sides by space, the opposite of relief. 

KILN - Enclosed containers of various sizes- built of refractor brick and heated by electricity, gas, oil, coal, propane, or wood to temperatures from 1500 F. to 2340 F. in which pots are fired. Some potters introduce chemicals into the kiln to influence the effects of the firing. Famed ceramist Beatrice Wood achieved a luster effect by throwing moth balls into the kiln

KILN WASH – A mixture of china clay and flint in water solution used to coat kiln shelves to protect them from dripping glaze

KILN SHELVES – The shelves inside a kiln that ceramic greenware is stacked on in the kiln. The shelves must be coated with kiln wash to prevent glazed pottery from sticking to the shelf

LEATHER HARD - Clay which is dried sufficiently to be stiff, but which is still damp enough to be joined to other pieces and be carved.

LIP-  the rim at the top of the vessel

Low Relief (also known as bas-relief sculpture) – this type of relief uses forms that project only slightly from the background and has a shallow depth

Luster a decoration that creates a metallic sheen to a glazed surface

Maquette a small, quickly made preliminary version of another larger piece to be created similar to a sketch used in drawing 

MATTE GLAZE – Dull surfaced glazes, lusterless and non-shiny

MATURING POINT – time and temperature needed to completely fire a glaze or clay object to the vitrified state

Neck the narrower part of the vessel between the shoulder and lip

Opening the process of making a hole in a centered piece of clay, this process allows the clay to be shaped into its basic form 

OXIDATION – (Compare to reduction) a firing atmosphere with ample oxygen. An electric kiln always gives an oxidizing fire.  In a wood or gas firing, the mixture of fuel and air is perfectly adjusted to give a clean burn. Acoma white ware is fired in oxidation.

OXIDES – metal oxides can be mixed with water and applied to the surface of clay. By varying the amount of material applied and rubbed off, the potter can achieve effects similar to stained wood. The most common stain is iron oxide (rust)

Paddling hitting the clay with a flat piece of wood to create strong joints, alter the shape and add texture to clay 

Piercing uses a variety of tools to cut holes in clay as decoration *Negative space * 

PINCH METHOD – Starting with a ball of clay the potter opens a hole into the ball and forms a bowl shape through a combination of stroking and pinching the clay.  Many coil-built pieces are constructed on top of a pinched bottom.

PLASTICITY - The property of a material enabling it to be shaped and to hold its form.

PORCELAIN – True porcelain was being made in china and Korea around 960 AD. Porcelain is a combination of kaolin pure, white, primary clay), silica and feldspar. A unique aspect of porcelain is that it can be worked as clay, but when fired properly reaches a state similar to glass. Primary qualities of porcelain are translucency and whiteness.

Potter’s Wheel A device used to throw clay forms or vessels. They can either be manual/ human powered (Kick Wheels) or electric.

PRESS MOLD - A plaster form which clay is compressed into, resulting in a repeatable shape or texture.

Pulling stretching or stroking plastic clay to elongate the clay, typically used in creating handles

PYROMETER – instrument used to record the exact temperature of the kiln

PYROMETRIC CONES – These are slender pyramids of ceramics material made in a graded series to melt and indicate when a firing is nearly completed or completed. In an automatic cutoff kiln, they trip a switch when they melt to cut the kiln off

RAKU - pottery is fired normally but removed when it is red hot and the glazed is molten. It is then usually placed in a bed of combustible materials and covered, creating intense reduction resulting in irregular surfaces and colors

REDUCTION – (compare to oxidation) a firing atmosphere with inadequate oxygen and large amounts of carbon (smoke or unburned fuel). What would have been copper oxide in an oxidation atmosphere will be pure copper in reduction. Reduction allowed the Chinese to develop the sangue de beouf red glazes and gives Raku its metallic finishes. In Indian pottery, the same piece in oxidation would be a terra cotta color

Rib A rubber, metal or wooden tool used to : • Smooth clay (such as blending coils) • facilitate wheel throwing of pottery forms. 

SCORED - Using a sharp tool to scratch the clay before it is attached to another piece of clay. Making xxx’s and /////’s.

SGRAFFITO - Carving a design on the body of the clay with a tool.  (texture patterns)      

SHELF SUPPORTS – Thick posts used to hold shelves in a kiln

SLIP – Liquid clay, water consistency that is used for joining together pieces of wet clay or adding designs to clay.

SLUMP MOLD - A plaster form which is used to support wet clay in the early stages of construction.

STILT – A triangular support for clay pieces that helps prevent glaze from melting on to shelves during a firing

STONEWARE – A high fire clay. Stoneware is waterproof even without glaze, the resulting ware is sturdier than earthware

TERRA COTTA –  a brownish-orange earthenware clay body commonly used for ceramic sculpture

UNDERGLAZE - Colored decoration applied to bisqued clay, then coated with a clear glaze. Typically made of clay slip and raw pigment.

VITRIFY – a glassy, non-porous state caused by heat or fusion

WEDGING - Method of kneading clay to make it homogenous; ridding the clay of all air pockets.