Glossary

Common terms that are used in hobby ceramics industry. If you can`t find the reference here e.mail us and we will try to help you.

alansunderland@houseofceramicsfrance.com

absorption is the amount of moisture that will soak into plaster when casting, or into bisque when glazing.
accenting is the process of emphasizing an area with lighter or darker colours by outlining or shading.
acrylic paint is used in a non firing process of decorating bisque.
add ons are added to the main casting piece.( example arm on figurine)
adherence is the ability of a colour to stay in place on a given surface
aging is the process of letting newly mixed casting slip to set this allows the slip to homogenize for better casting results
airbrushing is the process of applying colour with the use of a small air gun. used for shading and general decorating
alumina a major ingredient found in all clays and glazes
antiquing is a decorating process in which you remove applied colour to accentuate detail
antiquing gels are non toxic, non fired, waterbased colours that can be used to antique over all acrylic paints.
antiquing solvent is a thinner for airbrushing nonfired, oil based colours. it can also be used as a cleaner / conditioner for brushes used with oil based colours.
applique is a type of ceramic add on.
ball clay is an extremely fine grained plastic, sedimentary clay. although ball clay contains organic matter it usually is added to porcelain and white ware bodies to increase plasticity.
banding refers to applying colours to items in decorative bands. usually done with the aid of a banding wheel.
banding wheel usually refered to as a lazy jane. it is a hand operated turntable used for cake decorating.
basecoat generally an all over coat of colour on bisque on top of which decorating is done.
binder is material such as gum arabic, added to hold ceramicingredients together.
bisque refers to fired, unglazed objects of clay. generally bisque is clay that has been fired to a kiln setting of cone 04 sometimes called biscuit.
blistering refers to the appearance of broken bubbles found on the glazed surfaces of fired ceramic pieces.
body is the term used to describe any formula of clay. often called clay body, the composition of any clay body will change depending on where the clay is mined.
bone dry clay that has dried completely but is still unfired.
casting is the process of filling a plaster mould with casting slip (liquid clay) to create a clay object. once the plaster mould is removed the clay object is called greenware or unfired clay.
casting slip a liquid clay used in the process of forming objects with plaster moulds, also refered to as slip.
cavity the inside section of a plaster of paris mould, where the casting is formed.
ceramics clay forms that are fired in a kiln
china a term which usually refers to bone china also associated with white ware and porcelain
clay is a decomposed granite type rock that should be free of vegetable matter.
clay carbon is carbonless paper used for transfering designs onto greenware or unfired clay
cleaning greenware is the process of removing mould seam lines and imperfections from unfired clay objects.
casting is the term used when pouring moulds.
coats applications of ceramic colour by brush, sponge or spray which cover an entire piece or a specific area.
conditioning brush a brush lightly coated or dampened with a fluid to prepare it for the application specific type of colour or medium.
conditioning coat a thin coat of colour that will soak into greenware or bisque well.
cone a mixture of ceramic materials that is designed to soften and bend when the programmed mixture of time and temperature is reached in the interior of a kiln.
cone plaque a small clay cone holder used when cones are placed on shelves in the kiln.
cone temp the mixture of time and temperature at which the cone will bend.
cratering refers to moon like craters that may apear on a glazed surface.
crawling refers to a glaze defect in which the glaze pulls away or crawls away from the bisque, leaving bare bisque areas.
crazing refers to a glazed defect in which hairline cracks appear on a fired glazed surface.
crosshatch is a decorating technique that calls for appling alternate coats of colour at perpendicular angles.
decal a decal is a design printed with ceramic colour on special paper, which can be applied to the surface of ware and fired for permanency.
defloculant the alkaline substance which is added in extremely small ammounts to slip to make it more fluid.
dipping is a method of applying glaze by immersing piece in a container of glaze.
drybrushing is an effect achieved by applying non fired colours very lightly with an almost dry brush.
dry footing refers to leaving the bottom of a piece unglazed so that stilting is not necessary.
earthenware porous clay bodies which are fired to maturity at approx 2000 degrees f.
element the heating coil of an electric kiln.
ferrule is the metal band of a brush just below the bristles.
finger sand the gentle rubbing of the glazed surface to remove ridges.
fired finish a finish that must be fired to produce proper colour and surface finish.
firing is the process of maturing ceramic products by varying degrees of heat. firing usually takes place in a kiln.
firing chamber the interior of a kiln.
firing cycle the system of gradually raising and lowering the temperature of the kiln to properly free the ware.
flash is the undesirable transference of a soft glossy sheen on to unglazed ware when high fired glazed and unglazed ware are fired together.
flashing refers to shiny edges on ware, often produced by overfiring.
flow is the term used when referring to the running or moving qualities of a glaze.
flowing coat is used to describe applying colour with a well loaded brush
food safe a product that has been tested and determined to be safe for use on surfaces that come into contact with food.
foot refers to the base of any ceramic item.
furniture these are implements used to make full use of the kiln's capacity, e.g. shelves, posts and stilts
glaze is a fired finish consisting of a prepared mixture of frit that produces a glass-like surface when fired.
glaze brush is a brush with long full hairs for the application of glazes and underglazes
glaze butting is the term used to describe placement of two or more glazes in proximity on the same piece of work.
glaze trailing refers to the use of a fine tip squeeze bottle to trail one glaze over another to create a design
gloss a shiny gloss-like finish
graining is the process of creating a wood grained effect using thinned, non-fired, colours in long uneven patterns.
greenware is the term used for unfired clay articles
greenware drill is a small tool with a threaded point used for drilling holes in dry greenware.
greenware preparation involves the removal of mould seam lines and imperfections from unfired clay objects.
greenware saw is a small tool having a serrated edge for cutting dry greenware.
grit cloth is an abrasive cloth used for cleaning greenware or bisque.
grit sponge is a square sponge that has an abrasive surface on one side.
hard bisque is ware that has been fired to witness cone 04.
hard spots are areas that will reject colour and sometimes cause ware to have bare spots, commonly caused by improper greenware casting.
high fire refers to ceramic articles that are fired to witness cone 04 or higher, like stoneware or porcelain.
hot spot a section of the kiln that fires to a hotter temperature than the rest of the kiln.
immature bisque is ware that has been fired cooler than witness cone 06.
incising refers to the technique of cutting a clay surface to create a design.
keys are the series of notches and bumps carved into the excess plaster around the cavity mould to ensure a proper fit.
kiln is a heating chamber for hardening and maturing clay and glazes.
kiln furniture see reference to furniture - this is normally supplied when you buy your kiln.
kiln sitter - a device used with a pyrometric cone to shut off the kiln when conditions inside cause the cone to bend.
kiln wash is a coating used on the top of kiln shelves and kiln floors to protect them from glaze drippings.
lace tool a long pointed tool used when sapplying thin strands of clay.
lead release the amount of lead that is dissolved from the surface of the glaze which has been in contact with acid solutions.
leather hard is the term used to describe clay items that are damp but firm enough to handle without losing their shape.
liner brush is a brush used for fine lines and designer work.
loading refers to completely filling the brush with colour.
lustre is an overglaze that imparts an iridescent surface to the ware.
majolica technique refers to applying underglazes in a design over an unfired non-moving glaze
matt a soft finish with little or no shine.
matt glaze a dull surfaced glaze with no gloss but pleasant to the touch.
matured bisque a bisque that has been fired at the proper rate of heating and cooling to produce an even state of hardness throughout.
maturing point is the temperature needed to mature glaze or clay.
mini bars pyrometric cones that are used to measure the firing temperature of a kiln.
modelling clay is prepared clay used for hand modelling and using on a potter's wheel
mould or mold is a hollow plaster of paris from which articles are reproduced using slip.
mould strap devices made of cloth, rubber or metal used to tightly secure parts of the mould together during the pouring process.
nesting is the procedure of stacking greenware in a kiln during the bisque firing.
non fired finish a colour that is applied to bisque; these colours are never fired in the kiln.
non moving glazes are ceramic glazes that move or flow very little in the glaze firing.
non toxic is the term used to describe paint products conforming to us standard astm d 4236 to contain no material in sufficient quantities to be toxic or injurious to humans.
opaque refers to non transparent colour.
overglaze is a decorative finish applied over a fired glaze surface and made permanent by firing.
overglaze compatible is a glaze that will accept overglazes for a third firing. glazes that contain copper for added colour are not overglaze compatible.
palette knife is a flexible knife with no sharp point used for mixing or stirring colour.
peep holes are small holes in the side of the kiln used for viewing shelf cones and venting during the firing process.
pinholes are tiny holes penetrating a glazed surface.
plasticity refers to the pliability of modelling clay.
porosity refers to the permeability of fired or unfired clay.
posts are columns of refractory material used to support shelves inside the kiln.
pouncing is a technique in which you apply colour with a quick up and down movement with a brush or sponge.
pour holes a section at the opening of the mould used for pouring the slip into the mould cavity.
pouring is the process of filling plaster mouklds with casting slip to create the clay objects. once the plaster mould is removed the clay object is known as greenware.
prop another word for posts.
pyrometer is am instrument that indicates temperature in the kiln.
quarts flints or silica.
refactory material substances that have a high resistance to high temperatures.
rolling consistency refers to the consistency to which glazes are thinned for rolling inside ware
rolling glaze is a method of covering the inside area of ware by rolling thinned glaze inside.
running refers to the fluidity of a glaze at the point of maturity before cooling and hardening.
score refers to the process of scratching tiny criss-cross lines on areas of greenware that will be fastened together with a repair solution or slip.
scrub coat is a priming coat of thinned opaque underglaze or glaze.
sealers are spray or brush on coatings for use over non-fired colours to protect the surface and enhance the colours.
seam lines are formed on greenware where mould pieces join.
semi matt a satin like surface which has a semi-sheen to it.
semi opaque colours which generally only allow dark colours to show through.
sgraffitoing refers to the process of creating a design in ware by gently scratching through applied colour to reveal the colour or clay body beneath it or to create a carved design
shelf cone temperature the cone temperature that is fired on the shelf of the kiln. the amount of heat the ware actually receives.
shelf supports are columns of refactory material used to support shelves inside the kiln.
shelves are flat slabs of a special high temperature material on which ware is place inside the kiln.
shivering occurs when the glaze or underglaze and the clay body are incompatible. the clay body shrinks more than the colour, causing the colour to peel or break away.
shrinkage is the reduction in size of a clay object as a result of the firing.
silk sponges are used for decorating, and have short hairs on their surfaces and are soft and wet.
slip is the term used for clay in a liquid form
slip trailing is the process of applying slip in an applicator bottle to flow on a design for a raised effect.
smoking refers to the greying or discolouration of a glaze, caused by underfiring.
soaking cycle is the process of holding a certain temperature in the kiln chamber for an extended period.
soft bisque is ware that has been fired to witness cone 06 05.
solvent is a dissolving agent used in antiquing and to clean brushes with oil-based paints.
spattering is a method of applying small flecks of colour to ware usually with a bristle brush
sponging refers to the use of a sponge to apply colour directly to the surface of a piece of ware.
spray gun see air brush.
staggering refers to the process of applying separate successive coats of glaze by fractions of an inch to prevent glazes from flowing together.
stencil refers to the process of using paper perforated with a design through which colour can be brushed or sponged onto a surface.
stilts are supports used to separate glazed articles from a shelf during firing.
stippling is a method of applying colour by pouncing the tip of a brush loaded with colour against the ware.
stoneware a combination of clays which forms a stone like vitreous body during firing.
terracotta is a natural low fired clay. terracotta is also a colour name.
thermal expansion the expansion that occurs in glazes and clays when heated in a kiln.
thermal shock refers to extreme temperature change, usually caused by removing fired pieces too soon from the kiln.
tint is the process of lightly applying diluted colours over a basecoat or colouring a product with another product.
tipping involves touching tip of loaded brush with other colours for muted shading or accenting.
translucent refers to transparent colour, allowing colour underneath to show