Sagger

Vitreous

The state of a ceramic body which has been rendered non-porous by firing in an oven without the addition of a glaze.

Vitrification

When clay is fired one of the constituents-silica-is changed into glass and bonds all the other ingredients together. As vitrification proceeds the proportion of glassy bond increases and its porosity becomes lower. China is fully vitrified.

Ware

The general term for pottery. See also Flatware, Hollowware, Dinnerware etc.

Waster

A vessel or fragment which has been damaged during firing or later in the process of manufacture, and has been abandoned as waste.

Wedging

A method of kneading clay to make it homogenous by cutting and rolling.

Wet Sgraffito

Crude style of slipware where a pattern is drawn through a trailed slip while it is still wet.

Whirler

A piece of flatware in which the centre has fallen below the level of the foot rim. This manufacturing fault results and a ware that wobbles or whirls when set on a flat surface.

White ware

Undecorated glost ware. Also used to refer to white-bodied earthenware decorated or undecorated and white salt-glazed stoneware of the eighteenth century.

Sagger

A container made of fireclay into which the pottery to be fired is placed. The sagger protects the pottery from the flames and gasses inside the kiln during firing. By stacking the saggers inside the bottle kiln it was possible to load thousands of plates into the kiln at once.

Saltglaze

Staffordshire white or cream stoneware with semi-shiney by throwing rock-salt into the kiln at its peak temperature. The salt disassociates into sodium and chlorine ions at the oven temperature thus allowing the sodium to combine with the silica in the clayware to form a glaze that makes the ware non-porous.

Satin Glaze

A glaze with medium reflectance. The glaze is between matt and gloss.

Sgraffito

Style of slipware where a slip coat is used which is of a different colour to the body of the pot and is then decorated by cutting a pattern through the dry slip coat to reveal the contrasting colour of the body of the pot beneath.

Slab

Pressed or rolled flat sections of clay. They are used in building ceramics by hand.

Slip

Clay mixed with water, into a liquid, sieved to remove any particles. Slip is made as a means of accurately mixing the ingredients of a pottery body or to be used for casting ware in plaster moulds.

Slip casting

Casting with liquid clay.

Slipware

Pottery, usually earthenware, whose decoration is based upon the use of slip.

Slurry

A thick slip.

Soaking

Maintaining a low steady heat in the early stages of firing. The goal is to achieve a uniform temperature throughout the kiln.

Sprigging

Applying pre-molded relief motifs to the surface of a pottery object and connecting them by curled stems formed of threads of thinly rolled clay.

Spur

A triangular support used to separate plates within the sagger during firing in the kiln. The use of spurs can leave small spots on the surface of the plate. Usually three sets of three spur marks can be found on the underside of the rim and a single spur mark can be found on the upper side of the rim.

Stacking

Load a kiln to hold the maximum number of pieces.

Stain

Oxide and water, used as a colorant for bisque wear.

Stipple punching

An engraving technique where small dots are used to fill larger regions of a transfer ware pattern. The dots are created with a sharp punch that is driven into the copper plate.

Stoke China

Josiah Spode used this name for English bone china.

Stone China

Pale grey, fine porcelainous stoneware that is hard, dense and sometimes translucent. John and William Turner developed it in 1800. Miles Mason and Josiah Spode reintroduced it around 1812.

Terracotta

Unglazed porous earthenwares.

Throwing

Creating ceramic shapes on the potter’s wheel.

Throwing

A method of shaping holloware. A ball of clay is thrown onto a revolvong potter’s wheel, is centred and then shaped by the hands.

Transparent Glaze

Transmits light clearly.

Tyg

A drinking vessel with more than two handles or two set close together.
It is said to have been used in Staffordshire as another word for porringer, but its use to denote taller drinking vessels with several handles has not been traced further back than the nineteenth century.

Under-glaze

Decoration of ware before glazing and being fired.

Parian

Unglazed fine-grained porcelain.

Pearlware

Cream ware with a bluish tinge.

Peephole

A small observation hole in the wall or door of a kiln.

Pinch

Manipulate clay with your fingers in your palm to a hollow shape. Pinch pots are a popular beginners project.

Plasticity

The quality of clay. The better it can be manipulated into different shapes without cracking or breaking, the better the quality.

Porcelain

Term for a vitrified, translucent and white material. It has a transparent glaze. In Britain the term is used to distinguish the ware from bone China. Porcelain normally refers to ware made from a feldspathic body.

Potters Wheel

A device with either a manual (foot powered) or an electric rotating wheel head. The Potters tool to sit at and make pottery forms.

Pug mill

The mill, acting as a giant mincing machine, kneads, mixed and recycles the clay to emove all bubbles of air and give it an even consistency.

Pug

To mix.

Queen’s Ware

Josiah Wedgewood used this term for improved Creamware as presented to Queen Charlotte.

Reduction

Firing with no excess oxygen in the kiln - different colours can be obtained with some enamels dependant on the oxygen level present during the firing.

Redware

Red stoneware, usually unglazed and often decorated with applied motifs in relief.

Refractories

Materials which can withstand very high temperatures. For example fireclay.

Rib

A rubber, metal or wooden tool used to facilitate wheel throwing of pottery forms.

Technique for low fire glazing. An opaque tin glaze is applied to earthenware and painted with different coloured oxides.

Matching

A trade name to describe a replacement of a design made earlier either by the same or a different manufacturer.

Matt Glaze

A dull glaze surface, not very reflective when fired. It needs a slow cooling period or it may turn shiny.

Maturing Point

The temperature point at which the clay becomes hard and durable.

Mould

A plaster shape designed to pour slip cast into and let dry so the shape comes out as an exact replica of the mould.

Old Gold

A yellow colour applied to the edge of an object, usually earthenware, to give the semblance of a gilded edge.

On-glaze

Decoration of ware after the glaze has been fired.

Opaque Glaze

Non-transparent glaze, it covers the clay or glaze below it.

Ovalware

Oval shaped wares, for example meat platters.

Oxidation

Firing with a full supply of oxygen. It creates bright colours.

Jigger

A machine for making flatware like plates and saucers.

Jiggering

The process of shaping flatware with a the jigger machine. A pancake of clay is sandwiched between a revolving plaster mould (which forms the front of the plate) and a metalprofile-tool (which forms the back).

Jolley

A machine for making holloware like cups and bowls.

Jolleying

The proecess of shaping cups. The mould forms the outside and the profile-tool the inside.

Kaolin

A synonym for china clay.

Kilns

Heated chambers used for baking ware. They come in different sizes. The two main types are ‘intermittent’ and ‘tunnel’ kilns.

Kiln Furniture

Refractory posts and shelves used for stacking pottery in the kiln for firing.

Kiln Wash

Mixture of Kaolin, flint and water. It is painted on one side of the kiln shelves to separate any glaze drips from the shelf.

Lead Glaze

Transparent glassy glaze using lead oxide. Used on early English soft-paste and earthen wares.

Leather Hard

Clay that is past the stage of being plastic but not yet bone dry. The clay is still damp enough to join it to other pieces using slip. Handles can be applied to mugs for instance.

Lustreware

English ceramic decoration where pigments containing minute quantities of gold or platinum are applied.

Lithographs

Transfers used to decorate ware.

Gilding

Decorate china with gold or platinum.

Glaze

A smooth glossy surface by adding a thin coating of glass. Developed in clay ware by the fusion under heat of inorganic materials. It makes the porcelain and pottery waterproof and enhances the colour.

Glaze firing

The final phase of firing, this time with glaze.

Gloss firing

The firing given to ware after glazing.

Glostware

A biscuit (earthenware or porcelain after the first firing and before glazing) that has been glazed. Other names are white glost or white ware.

Green ware

Unfired pottery. Ready to be bisque fired.

Grog

Crushed pottery of already fired clay, then used to give a grogged surface.

Hollow Ware

Tableware like cups, bowls, teapots, creamers, and tureens. Typical to have depth and volume.

Incised

Carved inscriptions into a surface. Used for decorative purposes or to apply a mark.

A slab of refractory clay that is used to close or partially close the flue of a kiln.

Delft ware

Tin-glazed, porous bodied earthenware. Has a lead glaze made opaque by adding tin oxide.

Dry-Foot

To keep the foot or bottom of a pot free from glaze by waxing or removing the glaze.

Earthenware

Unlike china, it is fired at a relatively low temperature. It is not vitrified but is porous, opaque and not very strong. In order to hold liquids it must be glazed.

Enamelling

Enamel colours are metallic oxides made into to a fine powder with a flux added. The oxides are used for the decoration of glazed pottery.

Enamel Firing

A low temperature firing given to ware decorated on-glaze.

Englobe

Coloured clay slip used to decorate Greenwear or leather hard pieces before bisque firing. Clay and oxide and water.

Faience

A French term for any porous pottery body.

Feldspar

An ingredient of clays.

Fettle

Process where small flaws and imperfections are corrected.

Fire

The process of heating a clay object in a kiln to a specific temperature.

Filter Press

A press used to extract water from slip.

Firebrick

An insulation brick used to hold the heat in the kiln and withstand high temperatures.

Firing Range

The range of temperature at which a clay becomes mature or a glaze melts.

Firing

Baking ware in a kiln.

Flatware

Table wares that are more or less flat, Ware such as plates, saucers and platters.

Flint

Ground flint is mixed with some pottery bodies to control expansion in the kiln.

Flux

A melting agent causing silica to change into a glaze.

Foot

Base of a ceramic form.

Frit

A glaze material which is derived from flux and silica that are melted together and reground into a fine powder.

Ball Clay

Originally it was mined as lumps or balls, hence the name. The balls weighed up to 14kg. The clay is minedDevon and Dorset and has a plastic texture.

Bat

A flat disc made out of plaster, wood, or plastic which is affixed to the wheel head with clay or pins. Bats are used to throw pieces on that would be difficult to lift off the wheel head.

Biscuit Ware

Unglazed china that is not to be glazed but is hard-fired and vitreous. Also called bisque ware. Fired once to a temperature just before vitrification.

Body

Name used to describe the composite materials used for the production of any type of ceramic ware.

Blunger

A large vat in which raw materials in both liquid and solid form, the slip, are mixed together.

Bone China

The English form of porcelain. It is white, translucent and very strong. It consists of hard-paste porcelain plus bone-ash Bone China is famous for its translucency, strength and whiteness. The composition of bone china typically contains 45 - 50% cattle bone.

Bone Dry

Completely air dried.

Burnishing

Polishing the outside skin of a clay pot while greatly reducing its porosity. This final part of the process is done by hand, using a stone or a metal piece.

Cadogan Teapot

A lidless teapot.

Calipers

To measure the diameter of round forms this tool is used. To make the lid fit the calipher is used.

Ceramic

Originates from the Greek word “Keramos” - The art of making pottery. These days it is the general term for manufacturing articles prepared from pliable, earthy materials that are made rigid by high-temperature treatment.

China

The term originates from the country China as the Chinese were the inventors. In Britain, this usually refers to bone china but but is also used as the general term for porcelain. China consists of Hard-paste porcelain plus bone-ash (Calcium Phosphate).

China Clay

Derived from feldspar, it is the purest form of natural clay. It has a fine texture and, when fired, burns very white. In England it is mined in Cornwall.

China Stone

Also called Cornish Stone. It is feldspar less decomposed than china clay and is used as a flux.

China ware

Term used to describe the true porcelain exported from China.

Chinoiserie

Generic term used to describe wares using patterns with Chinese ornamental motifs, particularly those created by European artisans with little or no knowledge of Oriental art.

Clay

The essential raw material for ceramics. It is formed when rock breaks down under the action of the weather or by chemical processes- as in the case of china clay.

Clobbered Ware

A design produced in underglaze blue (often Chinese) to which enamel painting has been added. Designs printed with outlines for intentional painting in with either over or under glaze enamel are not considered clobbered ware.

Coil

Used in making pottery. A piece of clay rolled like a rope.

Compress

Pushing the clay down and together, forcing the particles of clay closer.

Composite Pots

Pots that were thrown or hand built in separate pieces and then assembled.

Crawling

A bare spot (from the shrinking of a glaze) on a finished piece where oil or grease prevents the glaze from adhering to pottery.

Crazing

Minute cracks in the glaze that occur upon cooling because the rate of shrinkage of the glaze is different from the rate of shrinkage of the body. It is the result of the glaze shrinking more than the clay body in cooling process.

These cracks can allow moisture and dirt to penetrate the glaze and discolour the ware.

Cross hatching

An engraving technique where thin parallel lines are used to fill areas of a transfer ware pattern. The width and spacing of the lines is used to adjust the tone of the resulting colour.

No one is alike, and no taste is the same. The same goes for tableware designs. Trained artists with an an extensive knowledge of patterns and color first design the decoration.

There are 3 phases where the decoration can be applied.

1. Before the ware is glazed
2. Under-glaze decoration
3. On-glaze decoration (after the glazing)

The last is the most common as more color can be applied

History of painting methods.

A long time ago, before 1790, all the decoration on china was hand-painted.
Only very exquisite piece of the very highest quality china are still decorated this way. It is a very labour intensive job which only real experts with a long experience can perform.

Freehand painting is one of the most skilled jobs in the pottery industry and it takes years of training to become expert.

3 Ways to Color the china

1. Ground laying

The ware is coated with a thin film of oil and powdered color is dusted over it. When fired, a very rich and rich solid background color is obtained.

2. Printing

This is transfer decoration using a single color. A copper plate or cylinder is engraved and color mixed with oil is spread over it. A transfer is taken on specially prepared tissue paper which is rubbed down onto the ware. The tissue paper is soaked off with water and the pattern is left. Prints are sometimes enriched by filing in the pattern with ceramic colors. In the industry this is known as ‘print and tint’.

3. Lithographs

Lithographs are transfers. They are printed on a paper base and covered in a plastic layer. When soaked in water, the plastic and the colors can be slid off and onto the ware. They are then carefully squeezed down to remove any bubbles of air that are trapped underneath. This is by far the most common way of decorating bone china.

Source: tableware tips