Advanced Ceramics Vocabulary

Flashcards of advanced ceramics vocabulary.

Ceramics

Objects made of clay hardened by heat.

Earthenware

A low-fire clay body typically fired between cones 06-04; terra- cotta and low-fire white clays are examples of low-fire clay bodies. Earthenware pieces are still porous after firing.

Air Dry Clay

A clay body that is soft and moldable but air dries to a hard state that requires no baking or firing; it remains porous but can be painted.

Potter

A person who makes pots, plates, and vessels from clay, either by hand or on a potter’s wheel.

Primary Clay

A clay that is found close to where it was formed in nature; primary clays are often white in color.

Clay

Rocks that have been broken down by weather and turned into tiny particles; water between these particles is what allows clay to be formed and shaped; when the water evaporates from the clay, it cannot be shaped any further.

Secondary Clay

A clay that is found far from where it was formed in nature; as the secondary clay travels by wind and water, it picks up other minerals (like iron) on its journey; secondary clays are often tan, buff, orange, or terra cotta colored and are frequently more plastic than primary clays.

Porcelain

A white high-fire clay body, porcelain is a primary clay that was first discovered in China; it is valued for its brightness, and if fired high enough, it can become translucent.

Ceramicist

A person who makes ceramics.

Pottery

Pots, plates, and vessels made from clay and fired in a kiln.

Stoneware

A mid to high-fire clay body fired between cones 5-7; high-fire stoneware is fired between cones 8-11. Stoneware clays contain fire clays that are refractory, meaning they can withstand high temperatures. These clays are fired to vitrification, which means they are not porous after firing and will not absorb water in use; therefore, they are used for dinnerware and pots.

Plasticine

An oil-based clay body; the oil prevents the clay from drying out. Plasticine is reusable and will not fully harden.

Grog

Crushed, unglazed pottery or brick used as an additive increase the clay’s strength.

Play Doughs

Soft and pliable clays made from various ingredients that are intended mainly for sensory play.

Slip

Liquid clay used to join pieces of clay together, it can be poured into molds or used for decorating.

Bone Dry

Clay pieces that have not been fired in the kiln.

Underglaze

Pigment mixed with a little bit of melter that is applied to raw clay or bisqueware and gives it color. Underglazes are applied like paint, and as the name implies, they go underneath a glaze; a clear glaze is often applied over the underglaze.

Greenware

Clay from which as much water as possible has evaporated from the piece; if you hold it to your cheek, it will seem dry instead of cold and damp. This clay looks and feels chalky and is very fragile; it is at this stage that clay pieces are fired in the kiln.

Glaze

A coating of glass that is applied to clay pieces, glaze can be brushed, dipped, or sprayed onto objects made of clay; when fired in a kiln, the glaze melts into a glass coating, turning it into a ceramic surface. Glaze forms a glossy or matte finish when fired to temperature.

Plastic

Clay that has started to dry but has some flexibility; it can still be carved, cut, and joined together, but it is hard like a block of cheese.

Glazeware

A clay piece that has been fired twice - once in a bisque firing and a second time in a glaze firing; it has a glossy or matte glasslike finish and a smooth texture.

Matte Finish

A dull, flat finish without a shine, a matte finish is often used on sculptural ceramic pieces because it allows the form be seen more easily.

Wet Clay

Clay that is wet enough that it can be shaped into forms by hand or on the wheel without breaking.

Bisqueware

An unglazed clay piece that has been fired in the kiln once at a low temperature and is ready to be glazed.

Gloss Finish

A shiny finish that reflects light and looks like a layer of glass; glossy finishes are often found on dinnerware.

Pinching

The process of squeezing a piece of clay between the thumb and the forefingers to make a hollow shape; pinch pots are made by pinching.

Coiling

Rolling or extruding a cylinder of clay to create a long, snake-like form; coils can be stacked on top of each other to create pots or sculptures.

Wedging

The process of pushing and pressing on clay to expel all air bubbles trapped in it and to bring the clay to a uniform, consistent moisture level.

Slab Building

Rolling clay into a flat sheet with either a rolling pin or slab rolling machine; clay slabs can be formed into pots or sculptures at the soft stage, or the slabs can be left to stiffen and assembled when leather hard.

Modeling

The act of creating three-dimensional (3-D) forms.

Additive

The process of joining pieces to create a form.

Subtractive

The process of removing pieces to create a form; carving is an example of the subtractive process.

Hollowing

Removing the inside from a form.

Relief

A sculpture that projects from a flat surface.

Slump Molding

Draping a slab of clay into a form to shape it.

Hump Molding

Laying a slab of clay over the top of a form to shape it.

Extruding

The process of forcing clay through an opening in a die to give it a shape.

Slip Casting

Pouring liquid clay into a plaster mold to create a form.

Throwing

The process of creating a pot on the potter’s wheel using your hands and water.

Score/Scoring

Scraping small lines into a piece of clay to roughen the surface prior to joining two pieces together; slip is applied to the scoring lines, and the two pieces are then smoothed together.

Kiln

A furnace or oven for firing clay sculptures and pottery; some kilns are gas fired while others use electricity or burn wood, all giving different firing results.

Reduction Firing

Reduction firings typically happen in gas kilns. In a reduction firing, oxygen is prevented from interacting with the glazes as they melt. This is done by closing the damper on the chimney a bit to cause the fuel in the kiln to burn less efficiently. Glazes fired in reduction result in mottled, rich, earthy colors. Often the iron from the clay body shows through the glaze as speckles.

Kiln Firing

The process of maturing ceramics by heating them in a kiln, firing makes the clay objects permanent.

Cone

Pyrometric devices used to gauge heat-work during the firing of ceramic materials. The cones, often used in sets of three, are positioned in a kiln with the wares to be fired and provide a visual indication of when the wares have reached a required state of maturity - a combination of time and temperature.

Low-Fire

Ceramics fired in the cone 06-04 range are considered low-fire. Low-fire works are typically fired to less than 1950 degrees Fahrenheit. Examples of low-fire clays are terra cotta and low-fire white clay bodies. Low-fire ceramic objects are still porous and can absorb water.

Mid-Fire

Ceramics fired in the cone 5-7 range. The clay used in mid-fire ceramics is stoneware. Glazes fired in this range in an electric kiln often yield bright colors. If an appropriate midfire clay and glazes are used, the works produced will be vitrified and safe to use for dinnerware.

High-Fire

Ceramics fired in the cone 9-11 range. High-fire works are often fired in gas kilns. While firing at this heat in electric kilns is possible, doing so wears out the heating elements in the kiln more quickly, leading to more frequent replacement. Stoneware and porcelain are examples of clay bodies used in high-fire ceramics.

Vitrified

When a clay object becomes glasslike from being fired in a kiln.

Oxidation Firing

Typically done in an electric kiln but can also be done in a gas kiln. Oxygen is free to interact with the glazes when firing, resulting in glazes that are bright in color.

Impressing

Pushing a clay stamp or textured object into a piece of clay to decorate it.

Trimming

Removing excess clay from a form that was thrown on the potter’s wheel.

Painting

Applying glaze or slip with a brush.

Glazing

Pouring, dipping, spraying, or applying glaze with a brush.

Oxides

Ground up metallic minerals, such as red iron oxide.

Stains

Pigments that come from minerals and oxides that have been ground into a powder.

Slip Trailing

Applying colored liquid clay with a bulb syringe to decorate a clay object.

Wedging

The process of pushing and pressing on clay to expel all air bubbles trapped in it and to bring the clay to a uniform, consistent moisture level.

Burnishing

Smoothing clay with a stone, plastic bag, or a finger to give it a smooth, polished finish.

Bat

A flat, removable disc attached to a potter’s wheel that allows a potter to throw and remove a piece from the wheel without distorting its shape.

Sgraffito

The act of carving through one layer of clay or underglaze to expose a different colored clay below it.

Centering

The act of pushing a piece of clay into the center of the potter’s wheel; this is done before the clay is opened and a wall is raised.

Incising

Decorating a clay object with a series of cuts.

Collaring

The act of narrowing the opening on a cylinder that is thrown on the potter’s wheel.

Carving

Using a tool to remove small clay pieces from a larger whole piece in order to create a form or finished artwork.

Neck

The thinner part of a vase, bottle, or pitcher that is located above the larger body or belly of the pot.

Piercing

Cutting or poking holes through a piece of clay.

Foot

The bottom of a pot, a foot is often trimmed into pottery when it is at the leather hard stage.

Shard

A broken fragment of pottery.

Base

The bottom part on which something rests or is supported.

Shrinkage

Clay objects get smaller in size throughout the drying and firing process; the average shrinkage rate for clay objects is 12.5 percent.

Dipping

The act of submerging a clay piece into a glaze or slip.

Wax Resist

The bottoms of pots are dipped into warm wax to repel glaze from sticking to the waxed areas; this keeps the bottom of the pot free from glaze so that it does not stick to the kiln shelf when fired. Wax resist can also be used for decorative purposes, if it is applied between layers of glaze.

Frit

A mixture of silica and fluxes melted at high temperature and then poured into water to cool, this mixture is then ground into a powder and used in glaze recipes; frits are often more consistent in their behavior in a glaze than the raw materials they are made from.

Flux

A melter; in a glaze recipe, the flux lowers the melting temperature of the glass, allowing it to melt at temperatures that can be reached in a kiln.

Refractory

The ability to withstand high heat without deforming; kiln bricks are refractory in nature.

Tiles

A use of clay.

Mosaics

A use of clay.

Bricks

A use of clay.

Roofs

A use of clay.

Sculptures/Figurines

A use of clay.

Pottery containers

A use of clay.

Plates

A use of clay.

Bowls

A use of clay.

Cups

A use of clay.

Mugs

A use of clay.

Serving Dishes

A use of clay.

Teapots

A use of clay.

Jugs

A use of clay.

Planters

A use of clay.

Vases

A use of clay.

Urns

A use of clay.

Vessels

A use of clay.

Potter's Wheel

A tool or piece of equipment used in ceramics.

Sgraffito Tool

A tool or piece of equipment used in ceramics.

Extruder

A tool or piece of equipment used in ceramics.

Wire Tool

A tool or piece of equipment used in ceramics.

Slip Brush

A tool or piece of equipment used in ceramics.