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American Heritage Dictionary:
pot·ter·y |
[French poterie, from Old French, from potier, potter, from pot, pot. See potiche.]
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Britannica Concise Encyclopedia:
pottery |
For more information on pottery, visit Britannica.com.
Gale's How Products Are Made:
How is pottery made? |
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Sidebar: This lovely, stout stoneware teapot is the work of Josiah Wedgwood and Co., of Staffordshire, England, perhaps the best known of British pottery companies of the nineteenth century. Teapots and associated cups became very popular about the mid-1700s because of the development importance of the "tea" and its ceremony. Thus, a mainstay of porters in the eighteenth century was the teapot and cup sets. Josiah Wedgwood was not content to simply supply pottery rather haphazardly. He knew there was a large market for high-quality, attractive pottery and he certainly would do his best to regularize the product and develop some new products people just had to have. He was one of the first potters to sell his wares in advance through orders, thus creating a sample or "stock" product. Since his products had to be uniform, he developed glazes that would give consistent results and divided the work process into many different steps so that one worker would not have a tremendous impact on the finished product. Particularly important to Wedgwood was the work of the modeller and the artist, who made the prototype shapes and designs for Wedgwood. Wedgwood discovered that these artists could provide designs for new pottery that looked antique, and these neo-classicol pieces were the mainstay of his business for many years. Nancy EV Bryk |
Background
Pottery is clay that is modeled, dried, and fired, usually with a glaze or finish, into a vessel or decorative object. Clay is a natural product dug from the earth, which has decomposed from rock within the earth's crust for millions of years. Decomposition occurs when water erodes the rock, breaks it down, and deposits them. It is important to note that a clay body is not the same thing as clay. Clay bodies are clay mixed with additives that give the clay different properties when worked and fired; thus pottery is not made from raw clay but a mixture of clay and other materials.
The potter can form his product in one of many ways. Clay may be modeled by hand or with the assistance of a potter's wheel, may be jiggered using a tool that copies the form of a master model onto a production piece, may be poured into a mold and dried, or cut or stamped into squares or slabs. The methods for forming pottery is as varied as the artisans who create them.
Pottery must be fired to a temperature high enough to mature the clay, meaning that the high temperature hardens the piece to enable it to hold water. An integral part of this firing is the addition of liquid glaze (it may be painted on or dipped in the glaze) to the surface of the unfired pot, which changes chemical composition and fuses to the surface of the fired pot. Then, the pottery is called vitreous, meaning it can hold water.
History
Potters have been forming vessels from clay bodies for millions of years. When nomadic man settled down and discovered fire, the firing of clay pots was not far behind. Pinch pots, made from balls of clay into which fingers or thumbs are inserted to make the opening, may have been the first pottery. Coil pots, formed from long coils of clay that are blended together, were not far behind. These first pots were fired at low temperatures and were thus fragile and porous. Ancient potters partially solved this by burnishing the surfaces with a rock or hard wood before firing. These low-temperature fired pots were blackened by these fires. Decoration was generally the result of incisions or insertions of tools into soft clay. Early potters created objects that could be used for practical purposes, as well as objects that represented their fertility gods.
The civilizations of ancient Egypt and the Middle East utilized clay for building and domestic use as early a 5000 B.C. By 4000 B.C., the ancient Egyptians were involved in pottery on a much larger scale. They utilized finer clays and fired the pieces at much higher temperatures in early kilns that removed the pots from the direct fire so they were not blackened from the fire. Bricks from clay were used as building material as well. The ancient Chinese produced black pottery by 3500 B.C. with round bases and plaited decoration. Closer to 1000 B.C. the Chinese used the potter's wheel and developed more sophisticated glazes. Their pottery was often included in funeral ceremonies. In the first millennium B.C., the Greeks began throwing pots on wheels and creating exquisite forms. Pre-Colombians, ancient Iberians, the ancient Romans (who molded pottery with raised decoration), and the ancient Japanese all created beautiful pottery for domestic use as well as for religious purposes.
Until the mid-eighteenth century, European potters generally sold small quantities of completed wares at a market or through merchants. If they wanted to sell more, they took more wares to market. However, British production potters experimented with new body types, perfected glazes, and took orders for products made in factories rather than taking finished goods to the consumer. By the later eighteenth century, many fellow potters followed suit, experimenting with all kinds of new bodies and glazes. Molds were used to make mass quantities of consistent product so that the consumer could be assured of the look of this piece.
Raw Materials
Its primary mineral is kaolinite; clay may be generally described as 40% aluminum oxide, 46% silicon oxide, and 14% water. There are two types of clays, primary and secondary. Primary clay is found in the same place as the rock from which it is derived—it has not been transported by water or glacier and thus has not mixed with other forms of sediment. Primary clay is heavy, dense, and pure. Secondary or sedimentary clay is formed of lighter sediment that is carried farther in water and deposited. This secondary clay, a mixture of sediment, is finer and lighter than primary clay. Varying additives give the clay different characteristics. Clay comes to a production potter in one of two forms—as a powder to which water must be added, or with water already added. Large factories purchase the clays in huge quantities as dry materials, making up the clay batch as needed each day.
Glazes are made up of materials that fuse during the firing process making the pot vitreous or impervious to liquids. (Ceramics engineers define vitreous as a pot that has a water absorption rate of less than 0.5%.) Glazes must have three elements: silica, the vitrifying element (converts the raw pottery into a glasslike form)—is found in ground and calcined flint and quartz; flux, which fuses the glaze to the clay; and refractory material, which hardens and stabilizes the glaze. Color is derived by adding a metallic oxide, including antimony (yellows), copper (green, turquoise, or red), cobalt (black), chrome (greens), iron, nickel, vanadium, etc. Glazes are generally purchased in dry form by production potters. The glazes are weighed and put into a ball mill with water. The glaze is mixed within the ball mill and grinds the glaze to reduce the size of the natural particles within the glaze.
Design
Pottery factories include art directors whose job it is to conceive marketable goods for the pottery company. Generally the art director, working with marketers, develops or creates an idea of a new creation. (Interestingly, many pottery companies are reproducing old forms popular decades ago such as brightly-colored Fiesta Ware so that new design is not necessary or desirable in all cases.) The art director then works with a clay modeler, who produces an original form of the creation to the art director's specifications. If the form is deemed a viable candidate for production, the mold maker makes a plaster master for the jiggering machine (which essentially traces a master shape onto a production piece) or a hollow into which clay is poured in order to form a production piece.
The Manufacturing
Process
Mixing the clay
Jiggering
Slip casting
Glazing
Firing
The kiln changes the glaze into a glass-like coating, which helps make the pot virtually impervious to liquid. Single-color production pottery requires only one firing with the new kilns and glazes. (Many glazes require that the greenware be fired once and made into a bisque or dull white, hard body, then glazed and fired again; however, this is not necessary with some new production glazes.)
Quality Control
All raw materials are checked against the company's established standards. Clays must contain the ingredients required by the product and ordered by the company. Glazes must be as pure as possible and are checked for correct shade, viscosity, gravity, etc. Kiln temperature must be carefully monitored with heat cones and thermocoupies, etc. And each human involved in production uses their eyes to monitor against inferior products.
Byproducts/Waste
There are no harmful by-products resulting from the production of pottery. Clay scraps and imperfect pieces produced off the jiggering machine or from slip casting may be re-mixed and re-used. Glazes must be lead-free as required by the Food and Drug Administration (FDA), and glazes are tested inhouse to assure the FDA that they contain neither cadmium nor lead. All glazes may be touched by the human hand are not harmful in raw state.
Where to Learn More
Books
Barber, Edwin Atlee. The Pottery and Porcelain of the United States. New York: G. P. Putnam's Son's, 1893.
Chavarria, Joaquim. The Big Book of Ceramics. New York: Watson-Gupthill, 1994.
Forty, Adrian. Objects of Desire. New York: Pantheon Books, 1986.
Hiller, Bevis. Pottery and Porcelain 1700-1914. New York: Meredith Press, 1968.
[Article by: Nancy EV Bryk]
McGraw-Hill Science & Technology Encyclopedia:
Pottery |
Vessels made entirely or partly of clay, and fired to a strong, hard product; occasionally, the term refers to just the lower grades of such ware. Pottery may be glazed or unglazed. See also Ceramics; Glazing.
Grades of pottery (such as china, stoneware, earthenware, and other special types) are distinguished by their color, strength, absorption (the weight of water soaked up when the piece is submerged, expressed as a percentage of the original weight), and translucency (ability to transmit light). All these properties refer to the material or “body” under any glaze present. See also Porcelain.
Absorption is due to the presence of open pores or voids in the fired material into which water can penetrate; in general, the higher the firing temperature, the lower the absorption. Body color is determined mainly by raw-material purity. Strength depends on the porosity and also on the amount and type of glass and crystals developed in the body on firing. Translucency is obtained in products in which there is low porosity and little differences in index of refraction between the glass and crystals in the body. See also Clay.
Bible Dictionary and Concordance:
Pottery |
The use of clay for manufacturing various kinds of vessels and other artifacts is one of the oldest crafts known to mankind. The raw material is abundantly found and pliable, the heat needed for firing is not so high as to require a complicated installation, the process of preparation is rather simple, and a considerable skill can be obtained after a short period of training. In addition, the softness of the material enables the creation of many shapes, and the chemical features of the clay make it possible to add to it painted decorations, seal impressions and various ornaments expressing religious ideas.
Pottery vessels were most common. Their main use was in dwellings, where they were utilized for cooking, baking and storing. However they were also utilized for public purposes. Storage jars were found in royal storehouses, where the supplies of the kingdom were kept. They were also used as containers for goods for international trade. Special types of vessels – ornamented stands, goblets, kernoi etc. – were made as cultic objects.
Pottery workshops were probably to be found in every region of ancient Israel. Different workshops created different shapes and had varying techniques. However, the art of pottery-making was rather similar throughout ancient Israel. Differences are noticeable mainly during the period of the divided monarchy. Constant connections with neighboring countries and with the coastal area led to individual influences on pottery making.
1. Any fired clayware which is produced by a clay worker.
2. The low-fired, porous, colored body ware, in contrast to white or buff-colored earthenware.
Oxford Dictionary of Archaeology:
pottery |
Clay that has been fashioned into a desired shape and then dried to reduce its water content before being fired or baked to fix its form. At temperatures of about 400°C water begins to be lost from the molecules forming the clay and at this point the clay cannot be returned to a plastic state through rehydration. At around 1 000°C the clay molecules begin to fuse, and at higher temperatures still the minerals vitrify into a solid mass.
Pottery is made in many different ways either by hand or using a potter's wheel. Because of the widespread availability of usable clay, pottery was independently invented in many parts of the world at different times.
Columbia Encyclopedia:
pottery |
Types of Pottery
It usually falls into three main classes-porous-bodied pottery, stoneware, and porcelain. Raw clay is transformed into a porous pottery when it is heated to a temperature of about 500°C. This pottery, unlike sun-dried clay, retains a permanent shape and does not disintegrate in water. Stoneware is produced by raising the temperature, and porcelain is baked at still greater heat. In this process part of the clay becomes vitrified, or glassy, and the strength of the pottery is increased.
Methods of Production
Pottery is formed while clay is in its plastic form. Either a long piece of clay is coiled and then smoothed, or the clay is centered upon a potter's wheel (used in Egypt before 4000 B.C.) that spins the clay while it is being shaped by the hand, or thrown. Decoration may be incised, and the piece is allowed to dry to a state of leather hardness before firing it in a kiln. The type of finish, depending on the kind or number of glazes, dictates the total number of firings. When slip and graffito are used, they are applied before the first firing. There are two types of fires-reducing and oxidizing. The former removes oxygen while the latter, a smokeless fire, adds it. Reduction and oxidation change the color of the fired clay and gave early potters their palette of red, buff, and black.
History
Early History
Pottery is one of the most enduring materials known to humankind. In most places it is the oldest and most widespread art; primitive peoples the world over have fashioned pots and bowls of baked clay for their daily use. Prehistoric (sometimes Neolithic) remains of pottery, e.g., in Scandinavia, England, France, Italy, Greece, and North and South America, have proved of great importance in archaeology and have often supplied a means of dating and establishing an early chronology. Some of the oldest pottery has been found in Japan and China, dated to at least 16,000 and 17,500 years old respectively. Pottery has also been of value as historical and literary records; ancient Assyrian and Babylonian writings have been inscribed upon clay tablets. Simple geometric patterns in monochrome, polychrome, or incised work are common to pottery of prehistoric and primitive cultures.
Pottery of the Ancient Mediterranean
By 1500 B.C. the use of glazes, such as the famous greens and blues, was known in Egypt. Especially noteworthy is the early Aegean pottery of the Minoan and Mycenaean periods with its curvilinear, painted decoration. In Assyria and Neo-Babylonia, painted and glazed bricks were in common use. The Ishtar gate in Babylon, with its ceramic reliefs, is an early example of the majolica technique.
The Greek vases (800-300 B.C.), famous for symmetry of form and beauty of decoration, include red, black, and varicolored examples. The last were for tombs only, as the colors were painted, unfired, and easily marred. The red ware is decorated with black figures, or the ground is black and the figures shown red. Water, oil, and wine jars were numerous. Of the Greco-Roman wares, the Arretine or Samian, also a red ware, was molded after first being turned on the wheel to the size of the mold, which carried the decoration in intaglio.
Pottery of Asia
Painted pottery of the Neolithic period has been found in China. By the 2d cent. B.C. the Early Han period had developed a green glaze which may have come from the Middle East. In the Sui period (A.D. 581-618) and the T'ang period (618-906), porcelain and porcelaneous ware (the envy of the Western world) began to be made and exported to Korea and Japan and to the Islamic world. Technical knowledge, however, was not exchanged, and Islam made no true porcelain.
Islamic pottery making was centered at Baghdad in the 10th cent. Blue and green clear glazes were used, and lusterware was first employed as an overglaze. Lusterware was highly developed under the Fatimites in Egypt (969-1171), and the technique continued in use at major pottery centers over the centuries that followed. During the 13th cent. Mongol domination of Persia brought renewed Chinese influence to Islamic pottery making. Fine examples of Hispano-Moorish pottery date from the 14th cent. Islamic architecture in the 15th cent. utilized ceramic tile in immense quantities, as on the Blue Mosque at Tabriz.
Pottery of Europe
In Europe there was little pottery of great aesthetic importance before the 15th cent., except perhaps some German stonewares. Majolica was mainly developed in Italy and from there spread to Spain, France (where it was called faience), and to Holland (where it came to be known as delftware). Majolica and stoneware were the main pottery forms in Europe until the advent (18th cent.) of porcelain.
Pottery of the Americas
Prehistoric pottery found in Peru, Mexico, and the SW United States reveals a high degree of skill in color, form, and decorative motifs. Baked-clay work by colonists in North America began in 1612 with the making of bricks and tiles in Virginia and Pennsylvania. In these states and among the Dutch settlers of New York, potteries were soon established. The first whiteware was made in 1684. A stoneware factory was opened in New York in 1735, and c.1750 the Jugtown pottery of North Carolina was first produced. Terra-cotta works were operating in Massachusetts and Pennsylvania after the middle of the 18th cent. Palatinate refugees produced slip-decorated and graffito earthenware, and their product formed the foundation of Shenandoah pottery.
In Philadelphia fine china was made (1769) for the first time in America. The potteries of Bennington, Vt., which opened in 1793, were known especially for their stoneware jugs; a variety of stoneware was also produced in several locations in New York state. East Liverpool, Ohio, since 1839 one of the foremost centers of the industry, produced the first American Rockingham ware. Also widely produced in the United States were redware, ironstone, and yellowware. Another center, begun in 1852 at Trenton, N.J., made fine Belleek or eggshell china. The Centennial Exposition of 1876 in Philadelphia and the World's Columbian Exposition of 1893 in Chicago did much to awaken native consciousness of pottery as a form of art.
Modern Pottery
American art pottery flourished in the first half of the 20th cent., with works created by a variety of artisans, many of whom were employed by companies such as the Rookwood Pottery and Cincinnati Art Pottery. Much collected in the decades that followed, this art pottery was created in such styles as art nouveau, arts and crafts, and art deco. In addition, many of the major artists of the 20th cent. created exquisite ceramic works. Especially notable are those by Picasso, Matisse, and Miró. In spite of the continuing development of mass-production techniques and synthetic materials, the demand for hand-crafted ware of fine quality has not diminished. A variety of artisans make utilitarian objects as well as works of art using many methods of pottery production. Moreover, indigenous peoples, notably native Americans, continue to create a number of vessels adapted from traditional forms.
Bibliography
See L. A. Boger, The Dictionary of World Pottery and Porcelain (1970); W. E. Cox, Book of Pottery and Porcelain (2 vol., rev. ed. 1970); E. Cooper, A History of Pottery (1973); G. Savage and H. Newman, An Illustrated Dictionary of Ceramics (1974); R. Fournier, The Illustrated Dictionary of Pottery Decoration (1986).
Saunders Veterinary Dictionary:
potteries |
Possible source of fluorine, used in glazes and art work, causing poisoning of livestock grazing on surrounding contaminated pasture.
Random House Word Menu:
categories related to 'pottery' |
Wikipedia on Answers.com:
Pottery |
Pottery is the material from which the potteryware is made,[1] of which major types include earthenware, stoneware and porcelain. The place where such wares are made is also called a pottery (plural "potteries"). Pottery also refers to the art or craft of the potter or the manufacture of pottery. [2] [3]
The definition of pottery used by ASTM is "all fired ceramic wares that contain clay when formed, except technical, structural, and refractory products."[4] Some archaeologists use a different understanding by excluding ceramic objects such as figurines which are made by similar processes, materials and the same people but are not vessels.[5]
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Contents
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Pottery is made by forming a clay body into objects of a required shape and heating them to high temperatures in a kiln which removes all water from the clay, which induces reactions that lead to permanent changes including increasing their strength and hardening and setting their shape. A clay body can be decorated before or after firing. Prior to some shaping processes, clay must be prepared. kneading helps to ensure an even moisture content throughout the body. Air trapped within the clay body needs to be removed. This is called de-airing and can be accomplished by a machine called a vacuum pug or manually by wedging. Wedging can also help produce an even moisture content. Once a clay body has been kneaded and de-aired or wedged, it is shaped by a variety of techniques. After shaping it is dried and then fired.
Clay ware takes on varying physical characteristics during the making of pottery.
There are several materials that are referred to as clay. The properties of the clays differ in: Plasticity, the malleability of the body; porosity, the degree to which the fired pottery will absorb water; and shrinkage, the degree of reduction in size of a body as water is removed. The various clays also differ in the way in which they respond to different degrees of heat when fired in the kiln. Each of these different clays are composed of different types and amounts of minerals that determine the resulting pottery. There are wide regional variations in the properties of raw materials used for the production of pottery, and this can lead to wares that are unique in character to a locality. It is common for clays and other materials to be mixed to produce clay bodies suited to specific purposes. The two essential components of clay are Silica and Alumina which combine to form Aluminium silicate, also known as Kaolinite. Other mineral compounds in the clay may act as Fluxes to lower the melting point of the silica during firing. Following is a list of different types of clay used for pottery that are available in different regions of the world.[8]
Pottery can be shaped by a range of methods that include:
Hand building. This is the earliest forming method. Wares can be constructed by hand from coils of clay, combining flat slabs of clay, or pinching solid balls of clay or some combination of these. Parts of hand-built vessels are often joined together with the aid of slip, an aqueous suspension of clay body and water. Hand-building is slower than wheel-throwing, but it offers the potter a high degree of control over the size and shape of wares. The speed and repetitiveness of other techniques is more suitable for making precisely matched sets of wares such as tablewares although some studio potters find hand-building more conducive to create one-of-a-kind works of art.
The potter's wheel. In a process called "throwing" (coming from the Old English word thrawan which means to twist or turn,[10] a ball of clay is placed in the centre of a turntable, called the wheel-head, which the potter rotates with a stick, with foot power or with a variable-speed electric motor.
During the process of throwing, the wheel rotates rapidly while the solid ball of soft clay is pressed, squeezed and pulled gently upwards and outwards into a hollow shape. The first step of pressing the rough ball of clay downward and inward into perfect rotational symmetry is called centring the clay--a most important skill to master before the next steps: opening (making a centred hollow into the solid ball of clay), flooring (making the flat or rounded bottom inside the pot), throwing or pulling (drawing up and shaping the walls to an even thickness), and trimming or turning (removing excess clay to refine the shape or to create a foot).
Considerable skill and experience are required to throw pots of an acceptable standard and, while the ware may have high artistic merit, the reproducibility of the method is poor.[11] Because of its inherent limitations, throwing can only be used to create wares with radial symmetry on a vertical axis. These can then be altered by impressing, bulging, carving, fluting, and incising. In addition to the potter's hands these techniques can use tools, including paddles, anvils & ribs, and those specifically for cutting or piercing such as knives, fluting tools and wires. Thrown pieces can be further modified by the attachment of handles, lids, feet and spouts.
Granulate pressing: As the name suggests, this is the operation of shaping pottery by pressing clay in a semi-dry and granulated condition in a mould. The clay is pressed into the mould by a porous die through which water is pumped at high pressure. The granulated clay is prepared by spray-drying to produce a fine and free-flowing material having a moisture content of between about 5 and 6 per cent. Granulate pressing, also known as dust pressing, is widely used in the manufacture of ceramic tiles and, increasingly, of plates.
Injection Moulding: is a shape-forming process adapted for the tableware industry from the method long established for the forming of thermoplastic and some metal components.[12] It has been called Porcelain Injection Moulding, or PIM.[13] Suited to the mass production of complex-shaped articles, one significant advantage of the technique is that it allows the production of a cup, including the handle, in a single process, and thereby eliminates the handle-fixing operation and produces a stronger bond between cup and handle.[14] The feed to the mould die is a mix of approximately 50 to 60 percent unfired body in powder form, together with 40 to 50 percent organic additives composed of binders, lubricants and plasticisers.[13] The technique is not as widely used as other shaping methods.[15]
Jiggering and jolleying: These operations are carried out on the potter's wheel and allow the time taken to bring wares to a standardized form to be reduced. Jiggering is the operation of bringing a shaped tool into contact with the plastic clay of a piece under construction, the piece itself being set on a rotating plaster mould on the wheel. The jigger tool shapes one face while the mould shapes the other. Jiggering is used only in the production of flat wares, such as plates, but a similar operation, jolleying, is used in the production of hollow-wares such as cups. Jiggering and jolleying have been used in the production of pottery since at least the 18th century. In large-scale factory production, jiggering and jolleying are usually automated, which allows the operations to be carried out by semi-skilled labour.
Roller-head machine: This machine is for shaping wares on a rotating mould, as in jiggering and jolleying, but with a rotary shaping tool replacing the fixed profile. The rotary shaping tool is a shallow cone having the same diameter as the ware being formed and shaped to the desired form of the back of the article being made. Wares may in this way be shaped, using relatively unskilled labour, in one operation at a rate of about twelve pieces per minute, though this varies with the size of the articles being produced. Developed in the U.K. just after World War II by the company Service Engineers, roller-heads were quickly adopted by manufacturers around the world; they remain the dominant method for producing flatware.[16]
Pressure casting – specially developed polymeric materials allow a mould to be subject to application external pressures of up to 4.0 MPa–so much higher than slip casting in plaster moulds where the capillary forces correspond to a pressure of around 0.1 - 0.2 MPa. The high pressure leads to much faster casting rates and, hence, faster production cycles. Furthermore, the application of high pressure air through the polymeric moulds upon demoulding the cast means a new casting cycle can be started immediately in the same mould, unlike plaster moulds which require lengthy drying times. The polymeric materials have much greater durability than plaster and, therefore, it is possible to achieve shaped products with better dimensional tolerances and much longer mould life. Pressure casting was developed in the 1970s for the production of sanitaryware although, more recently, it has been applied to tableware.[17][18][19][20]
RAM pressing: A factory process for shaping table wares and decorative ware by pressing a bat of prepared clay body into a required shape between two porous moulding plates. After pressing, compressed air is blown through the porous mould plates to release the shaped wares.
Slipcasting: is often used in the mass production of ceramics and is ideally suited to the making of wares that cannot be formed by other methods of shaping. A slip, made by mixing clay body with water, is poured into a highly absorbent plaster mould. Water from the slip is absorbed into the mould leaving a layer of clay body covering its internal surfaces and taking its internal shape. Excess slip is poured out of the mould, which is then split open and the moulded object removed. Slipcasting is widely used in the production of sanitary wares and is also used for making smaller articles, such as intricately detailed figurines.
Pottery may be decorated in a number of ways including:
Additives can be worked into the clay body prior to forming, to produce desired effects in the fired wares. Coarse additives such as sand and grog (fired clay which has been finely ground) are sometimes used to give the final product a required texture. Contrasting coloured clays and grogs are sometimes used to produce patterns in the finished wares. Colourants, usually metal oxides and carbonates, are added singly or in combination to achieve a desired colour. Combustible particles can be mixed with the body or pressed into the surface to produce texture.
Agateware: Named after its resemblance to the quartz mineral agate which has bands or layers of colour that are blended together, agatewares are made by blending clays of differing colours together but not mixing them to the extent that they lose their individual identities. The wares have a distinctive veined or mottled appearance. The term "agateware" is used to describe such wares in the United Kingdom; in Japan the term "neriage" is used and in China, where such things have been made since at least the Tang Dynasty, they are called "marbled" wares. Great care is required in the selection of clays to be used for making agatewares as the clays used must have matching thermal movement characteristics.
Banding: This is the application by hand or by machine of a band of colour to the edge of a plate or cup. Also known as "lining", this operation is often carried out on a potter's wheel.
Burnishing: The surface of pottery wares may be burnished prior to firing by rubbing with a suitable instrument of wood, steel or stone to produce a polished finish that survives firing. It is possible to produce very highly polished wares when fine clays are used or when the polishing is carried out on wares that have been partially dried and contain little water, though wares in this condition are extremely fragile and the risk of breakage is high.
Engobe: This is a clay slip, that is used to coat the surface of pottery, usually before firing. Its purpose is often decorative though it can also be used to mask undesirable features in the clay to which it is applied. Engobe slip may be applied by painting or by dipping to provide a uniform, smooth, coating. Engobe has been used by potters from pre-historic times until the present day and is sometimes combined with sgraffito decoration, where a layer of engobe is scratched through to reveal the colour of the underlying clay. With care it is possible to apply a second coat of engobe of a different colour to the first and to incise decoration through the second coat to expose the colour of the underlying coat. Engobes used in this way often contain substantial amounts of silica, sometimes approaching the composition of a glaze.
Litho: This is a commonly used abbreviation for lithography, although the alternative names of transfer print or "decal" are also common. These are used to apply designs to articles. The litho comprises three layers: the colour, or image, layer which comprises the decorative design; the cover coat, a clear protective layer, which may incorporate a low-melting glass; and the backing paper on which the design is printed by screen printing or lithography. There are various methods of transferring the design while removing the backing-paper, some of which are suited to machine application.
Gold: Decoration with gold is used on some high quality ware. Different methods exist for its application, including:
Glaze is a glassy coating on pottery, the primary purposes of which are decoration and protection. One important use of glaze is to render porous pottery vessels impermeable to water and other liquids. Glaze may be applied by dusting the unfired composition over the ware or by spraying, dipping, trailing or brushing on a thin slurry composed of the unfired glaze and water. The colour of a glaze before it has been fired may be significantly different than afterwards. To prevent glazed wares sticking to kiln furniture during firing, either a small part of the object being fired (for example, the foot) is left unglazed or, alternatively, special refractory "spurs" are used as supports. These are removed and discarded after the firing.
Some specialised glazing techniques include:
Firing produces irreversible changes in the body. It is only after firing that the article or material is pottery. In lower-fired pottery, the changes include sintering, the fusing together of coarser particles in the body at their points of contact with each other. In the case of porcelain, where different materials and higher firing-temperatures are used, the physical, chemical and mineralogical properties of the constituents in the body are greatly altered. In all cases, the object of firing is to permanently harden the wares and the firing regime must be appropriate to the materials used to make them. As a rough guide, earthenwares are normally fired at temperatures in the range of about 1,000°C (1,830 °F) to 1,200 °C (2,190 °F); stonewares at between about 1,100 °C (2,010 °F) to 1,300 °C (2,370 °F); and porcelains at between about 1,200 °C (2,190 °F) to 1,400 °C (2,550 °F). However, the way that ceramics mature in the kiln is influenced not only by the peak temperature achieved but also by the duration of the period of firing. Thus, the maximum temperature within a kiln is often held constant for a period of time to soak the wares to produce the maturity required in the body of the wares.
The atmosphere within a kiln during firing can affect the appearance of the finished wares. An oxidising atmosphere, produced by allowing air to enter the kiln, can cause the oxidation of clays and glazes. A reducing atmosphere, produced by limiting the flow of air into the kiln, can strip oxygen from the surface of clays and glazes. This can affect the appearance of the wares being fired and, for example, some glazes containing iron fire brown in an oxidising atmosphere, but green in a reducing atmosphere. The atmosphere within a kiln can be adjusted to produce complex effects in glaze.
Kilns may be heated by burning wood, coal and gas or by electricity. When used as fuels, coal and wood can introduce smoke, soot and ash into the kiln which can affect the appearance of unprotected wares. For this reason, wares fired in wood- or coal-fired kilns are often placed in the kiln in "saggars", lidded ceramic boxes, to protect them. Modern kilns powered by gas or electricity are cleaner and more easily controlled than older wood- or coal-fired kilns and often allow shorter firing times to be used. In a Western adaptation of traditional Japanese Raku ware firing, wares are removed from the kiln while hot and smothered in ashes, paper or woodchips which produces a distinctive carbonised appearance. This technique is also used in Malaysia in creating traditional labu sayung.[25][26]
A great part of the history of pottery is prehistoric, part of past pre-literate cultures. Therefore, much of this history can only be found among the artefacts of archaeology. Because pottery is so durable, pottery and sherds from pottery survive from millennia at archaeological sites.
Before pottery becomes part of a culture, several conditions must generally be met.
Methods of forming: Hand-shaping was the earliest method used to form vessels. This included the combination of pinching and coiling.
Firing: The earliest method for firing pottery wares was the use of bonfires Pit fired pottery. Firing times were short but the peak-temperatures achieved in the fire could be high, perhaps in the region of 900 °C (1,650 °F), and were reached very quickly.[28]
Clay: Early potters used whatever clay was available to them in their geographic vicinity. However, the lowest quality common red clay was adequate for low-temperature fires used for the earliest pots. Clays tempered with sand, grit, crushed shell or crushed pottery were often used to make bonfire-fired ceramics because the coarser particles in the clay also acted to restrain shrinkage during drying, and hence reduce the risk of cracking.
Form: In the main, early bonfire-fired wares were made with rounded bottoms to avoid sharp angles that might be susceptible to cracking.
Glazing: The earliest pottery was not glazed.
The potter's wheel was invented in Mesopotamia sometime between 6,000 and 4,000 BCE (Ubaid period) and revolutionised the production of pottery.
Biscuit moulds were used to a limited extent as early as the 5th and 6th century by the Etruscans [29] and more extensively by the Romans [30].
Slipcasting, a popular method for shaping irregular shaped articles. It was first practised, to a limited extent, in China as early as the T'ang dynasty [31]
Transition to kilns: The earliest intentionally-constructed were pit-kilns or trench-kilns—holes dug in the ground and covered with fuel. Holes in the ground provided insulation and resulted in better control over firing. [32]
kilns: Pit fire methods were adequate for creating earthenware, but higher-fired stoneware and porcelain required more sophisticated methods of firing using high-fire kilns (see below kilns).
The earliest forms of pottery were made from clays that were fired at low temperatures in pit-fires or in open bonfires. They were hand formed and undecorated. Because the biscuit form of earthenware is porous, it has limited utility for storage of liquids. However, earthenware has a continuous history from the Neolithic period to today. It can be made from a wide variety of clays. Many of the clays that can be turned to pottery at low temperatures .[33] The development of Ceramic glaze which makes it impermeable makes it a popular and practical form of pottery making. The addition of decoration has evolved throughout its history.
Glazed Stoneware was being created as early as the 15th century BCE in China. This achievement coincided with kilns that could be fired at higher temperatures. [34]
Porcelain was first made in China during the Tang Dynasty (618-906 CE). Porcelain was also made in Korea and Japan around the 16th and 17th century AD after suitable kaolin was located in those countries. It was not created outside of the area until the 18th century.[35]
The earliest-known ceramic objects are Gravettian figurines such as those discovered at Dolní Věstonice in the modern-day Czech Republic. The Venus of Dolní Věstonice (Věstonická Venuše in Czech) is a Venus figurine, a statuette of a nude female figure dated to 29,000–25,000 BCE (Gravettian industry).[36] The earliest pottery vessels found include those excavated from the Yuchanyan Cave in southern China, dated from 16,000 BCE,[37] and those found in the Amur River basin in the Russian Far East, dated from 14,000 BCE.[38][39]
Other early pottery vessels include those made by the Incipient Jōmon people of Japan from around 10,500 BCE have also been found.[40][41] The term "Jōmon" means "cord-marked" in Japanese. This refers to the markings made on the vessels and figures using sticks with cords during their production.
It appears that pottery was independently developed in North Africa during the 10,000 BCE[42] and in South America during the 10,000 BCE[43]
The Far East, sometimes called the Orient, has excelled in all categories on the history of making pottery. Sherds have been found in China and Japan from a period between 12,000 and perhaps as long as 16,000 years ago.[37][44] In Japan, the Jōmon period has a long history of development of Jōmon Pottery which was characterized by impressions of rope on the surface of the pottery created by pressing rope into the clay before firing. Glazed Stoneware was being created as early as the 15th century BCE in China. Porcelain became a renowned Chinese export during the Tang Dynasty (618-906 CE) and subsequent dynasties.[45] Korean potters produced porcelain as early as the 14th century CE.[46] Koreans brought the art of porcelain to Japan in the 17th century CE.[47]
The secret of making such porcelain was sought in the Islamic world and later in Europe when examples were imported from the East. Many attempts were made to imitate it in Italy and France. However it was not produced outside of the Orient until 1709 in Germany.[48]
Pottery was in use in ancient India, including areas now forming Pakistan and northwest India, during the Mehrgarh Period II (5,500-4,800 BCE) and Merhgarh Period III (4,800-3,500 BCE), known as the ceramic Neolithic and chalcolithic. Pottery, including items known as the ed-Dur vessels, originated in regions of the Indus Valley and have been found in a number of sites in the Indus Valley Civilization.[49][50]
The earliest history of pottery production in the Near East can be divided into four periods, namely: the Hassuna period (7000-6500 BCE), the Halaf period (6500-5500 BCE), the Ubaid period (5500-4000 BCE), and the Uruk period (4000-3100 BCE).
The invention of the potter's wheel in Mesopotamia sometime between 6,000 and 4,000 BCE (Ubaid period) revolutionized pottery production. Specialized potters were then able to meet the expanding needs of the world's first cities.
Pottery making began in the Fertile Crescent from the 7th millennium BCE. The earliest forms, which were found at the Hassuna site, were hand formed from slabs, undecorated, unglazed low-fired pots made from reddish-brown clays.[51] Within the next millennium, wares were decorated with elaborate painted designs and natural forms, incising and burnished.
By 4000 BCE, the potters wheel was developed. Newer kiln designs could fire wares to 1,050 °C (1,920 °F) to 1,200 °C (2,190 °F) which enabled new possibilities and new preparation of clays. Production was now carried out by small groups of potters for small cities, rather than individuals making wares for a family. The shapes and range of uses for ceramics and pottery expanded beyond simple vessels to store and carry to specialized cooking utensils, pot stands and rat traps.[52]
As the region developed new organizations and political forms, pottery became more elaborate and varied. Some wares were made using moulds, allowing for increased production for the needs of the growing populations. Glazing was commonly used and pottery was more decorated.[53]
Civilization developed concurrently with the Fertile Crescent in the ancient Mediterranean islands around Greece from about 3200 to 1000 BCE and carried to Ancient Greece and Ancient Rome that is considered the Classical era in the Western world. The arts of these cultures eventually became a hallmark for Europe and the New World.
The Minoan pottery was characterized by elaborate painted decoration with natural themes.[54]
The classical Greek culture began to emerge around 1000 BCE featuring a variety of well crafted pottery which now included the human form as a decorating motif. The pottery wheel was now in regular use. Although glazing was known to these potters, it was not widely used. Instead, a more porous clay slip was used for decoration. A wide range of shapes for different uses developed early and remained essentially unchanged during the Greek history.[55]
In the Mediterranean, during the Greek Dark Ages (1,100–800 BCE), amphoras and other pottery were decorated with geometric designs such as squares, circles and lines. In the Chalcolithic period in Mesopotamia, Halafian pottery achieved a level of technical competence and sophistication, not seen until the later developments of Greek pottery with Corinthian and Attic ware.[citation needed]
The Etruscan pottery carried on the Greek pottery with its own variations.
The Ancient Roman pottery started by copying Greek and Etruscan styles but soon developed a style of its own.[56]
The distinctive Red Samian ware of the Early Roman Empire was copied by regional potters throughout the Empire.
Early Islamic pottery followed the forms of the regions which the Muslims conquered. Eventually, however, there was cross-fertilization between the regions. This was most notable in the Chinese influences on Islamic pottery. Trade between China and Islam took place via the system of trading posts over the lengthy Silk road. Islamic nations imported stoneware and later porcelain from China. China imported the minerals for Cobalt blue from the Islamic ruled Persia to decorate their Blue and white porcelain, which they then exported to the Islamic world.
Likewise, Islamic art contributed to a lasting pottery form identified as Hispano-Moresque in Andalucia (Islamic Spain). Unique Islamic forms were also developed, including Fritware, Lusterware and specialized glazes like Tin-glazing, which led to the development of the popular Maiolica. [57]
One major emphasis in ceramic development in the Muslim world was the use of tile and decorative tilework.
The early inhabitants of Europe developed pottery at about the same time as in the Near East, circa 5500–4500 BCE. These cultures and their pottery were eventually shaped by new cultural influences and technology with the invasions of Ancient Rome and later by Islam. The Renaissance art of Europe was a melding of the art of Classical era and Islamic art.
Most evidence points to an independent development of pottery in the Amerindian cultures, starting with their Archaic Era (3500–2000 BCE), and into their Formative period (2000 BCE-200 CE). These cultures did not develop the stoneware, porcelain or glazes found in the old world.
Northern Africa includes Egypt, which had several distinct phases of development in pottery. During the early Mediterranean civilizations of the fertile crescent, Egypt developed a unique non-clay-based high-fired ceramic which has come to be called Egyptian faience. [note 1]
The other major phase came during the Umayyad Caliphate of Islam, Egypt was a link between early center of Islam in the Near East and Iberia which led to the impressive style of pottery.
Sub-Saharan Africa had a distinctly different history with relatively less development of pottery.
Polynesia, Melanesia, and Micronesia
Pottery has been found in archaeological sites across the islands of Oceania. It is attributed to an ancient archaeological culture called the Lapita. A form of pottery called Plainware is found throughout sites of Oceania. The relationship between Lapita pottery and Plainware is not altogether clear.
Australia is sometimes counted as part of Oceania. However, it had a quite different development. The Aborigines of Australia were hunter-gatherer tribes and did not farm or cultivate crops. In keeping with these cultural features, they also never developed pottery. [58] After Europeans came to Australia and settled, they found deposits of clay which were analysed by English potters as excellent for making pottery. Less than 20 years later, Europeans came to Australia and began creating pottery. Since then, ceramic manufacturing, mass-produced pottery, and studio pottery have flourished in Australia. [59]
For archaeologists, anthropologists and historians the study of pottery can help to provide an insight into past cultures. Pottery is durable, and fragments, at least, often survive long after artefacts made from less-durable materials have decayed past recognition. Combined with other evidence, the study of pottery artefacts is helpful in the development of theories on the organisation, economic condition and the cultural development of the societies that produced or acquired pottery. The study of pottery may also allow inferences to be drawn about a culture's daily life, religion, social relationships, attitudes towards neighbours, attitudes to their own world and even the way the culture understood the universe.
Chronologies based on pottery are often essential for dating non-literate cultures and are often of help in the dating of historic cultures as well. Trace-element analysis, mostly by neutron activation, allows the sources of clay to be accurately identified and the thermoluminescence test can be used to provide an estimate of the date of last firing. Examining fired pottery shards from prehistory, scientists learned that during high-temperature firing, iron materials in clay record the exact state of Earth's magnetic field at that exact moment.
Although many of the environmental effects of pottery production have existed for millennia, some of these have been amplified with modern technology and scales of production. The principal factors for consideration fall into two categories: (a) effects on workers, and (b) effects on the general environment. Within the effects on workers, chief impacts are indoor air quality, sound levels and possible over-illumination. Regarding the general environment, factors of interest are fuel consumption, off-site water pollution, air pollution and disposal of hazardous materials.
Historically, "plumbism" (lead poisoning) was a significant health concern to those glazing pottery. This was recognised at least as early as the nineteenth century, and the first legislation in the United Kingdom to limit pottery workers’ exposure was introduced in 1899.[60] While the risk to those working in ceramics is now much reduced, it can still not be ignored. With respect to indoor air quality, workers can be exposed to fine particulate matter, carbon monoxide and certain heavy metals. The greatest health risk is the potential to develop silicosis from the long-term exposure to crystalline silica. Proper ventilation can reduce the risks, and the first legislation in the United Kingdom to govern ventilation was introduced in 1899.[60] Another, more recent, study at Laney College, Oakland, California suggests that all these factors can be controlled in a well-designed workshop environment.[61]
The use of energy and pollutants in the production of ceramics is a growing concern. Electric firing is arguably more environmentally friendly than combustion firing although the source of the electricity varies in environmental impact.[citation needed]
The English city of Stoke-on-Trent is widely known as The Potteries because of the large number of pottery factories or, colloquially, Pot Banks. It was one of the first industrial cities of the modern era where, as early as 1785, two hundred pottery manufacturers employed 20,000 workers.[62] For the same reason, the largest football club in the city is known as The Potters.[63]
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Translations:
Pottery |
Dansk (Danish)
n. - pottemagerværksted, lertøj
Nederlands (Dutch)
pottenbakkerij, aardewerk, ceramiek, het pottenbakken
Français (French)
n. - céramique, poterie
Deutsch (German)
n. - Töpferware, Keramik, Töpferei
Ελληνική (Greek)
n. - κεραμικά, είδη κεραμικής, αγγειοπλαστική, κεραμική, κεραμοποιείο
adj. - κεραμικός
Italiano (Italian)
ceramica, ceramico
Português (Portuguese)
n. - cerâmica (f), olaria (f)
adj. - cerâmico
Русский (Russian)
керамика, гончарная мастерская
Español (Spanish)
n. - loza, cerámica, alfarería, de loza, de cerámica
Svenska (Swedish)
n. - keramik, lergods, krukmakeri, porslinsfabrik
adj. - keramik-, keramisk, lergods-
中文（简体）(Chinese (Simplified))
陶器, 陶器厂, 陶器制造术
中文（繁體）(Chinese (Traditional))
n. - 陶器, 陶器廠, 陶器製造術
한국어 (Korean)
n. - 도기, 오지그릇, 도기제조법
日本語 (Japanese)
n. - 陶器類, 陶器製造, 陶器製造所, 陶器
العربيه (Arabic)
(الاسم) مصنع الفخار أو الخزف (صفه) آنيه فخاريه
עברית (Hebrew)
n. - כלי-חרס, בית-היוצר, בית-מלאכה לקדרות, קדרות
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| Bible Dictionary and Concordance. Illustrated Dictionary & Concordance of the Bible. Copyright © 1986 by G.G. The Jerusalem Publishing House, Ltd. All rights reserved. Read more |
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| McGraw-Hill Dictionary of Architecture & Construction. McGraw-Hill Dictionary of Architecture and Construction. Copyright © 2003 by McGraw-Hill Companies, Inc. All rights reserved. Read more |
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| Oxford Dictionary of Archaeology. The Concise Oxford Dictionary of Archaeology. Copyright © 2002, 2003 by Oxford University Press. All rights reserved. Read more |
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