pottery

Slab Construction

A pottery technique in which a form is built up by joining shapes cut from thick sheets of damp clay.

Just what is Clay?

Clay is a mix of naturally occurring materials made up primarily of fine-grained minerals. Think of very finely ground up rock. The fine partials of rock are suspended in water. More water makes the the clay softer to the touch, less water makes the clay harder to the touch. Different colors occur in clay because of impurities in the clay. Red clay is the result of Iron Oxide in the clay, while white clays get their color from Talc in the clay body.

Earthenware

Fired at a low temperature Relatively porous and soft. Most commonly found clay in nature Raw material used to make tiles, bricks, and most pottery products found across the globe. Earthenware has a low shrink factor and is porous, leaky, and stains easily. Good clay for making planters and oven steamers Raw state clay appears brown, red, gray or greenish When fired it ranges from red to tan to brown or black Two Types Pottery Semi Vitreous Earthenware, the type of clay with the lowest firing temperature of the three, is relatively porous and soft. It is the most commonly found clay in nature, and is the raw material used to make tiles, bricks, and most pottery products found across the globe. Earthenware clay contains a percentage of iron and mineral impurities high enough for it to mature at firing temperatures from "bonfire" heat at around 1300 degrees F, up to about 2120 degrees F (cone 018-cone 3*). In its raw state, the presence of iron oxide makes this clay appear brown, red, gray, or greenish. When fired, it's anything from red or tan to brown or black. Earthenware has a low shrink factor and is porous, leaky, and stains easily. Because of its porosity, earthenware is a good clay for making planters and oven steamers, yet would not work well for pitchers or vases.

Lenox

Lenox is the market leader in luxury tableware and gifts. The only manufacturer of fine bone china in the United States, Lenox has celebrated outstanding design and manufacturing for the 124 years and remains the premiere market destination for bridal, entertaining and gift giving. Also known for providing Presidential dinnerware to the White House, Lenox Corporation is an American company that markets its products primarily under the Lenox®, kate spade new york, Donna Karan Lenox, Marchesa by Lenox, L by Lenox®, Dansk® and Gorham® brands. www.lenox.com Lenox creates two colors of bone china, white and ivory. Although certain additives or pigments are used to create the ivory color in the finished product, in the slurry state, both clays are slightly gray. In order to tell them apart, the ivory mix is tinted with green vegetable dye, which will eventually burn out in the kiln. fact, Lenox made the first bone china to be used in the White House. Since then six different presidents have had tableware made by Lenox. Tabletop - Dinnerware, Crystal Stemware, Glassware, Flatware, Giftware, Bridal Giftware and Fine Tabletop Products, Manufacturer of Fine China for The White House, Luxury Goods - Licensed Brands Lenox has celebrated outstanding design and manufacturing for the past 124 years Lenox's 218,000-square-foot plant is located in Kinston , N.C. The Kinston plant uses an average of 4 million pounds of clay each year. The plant can produce 15,000 to 20,000 pieces of china daily. It has been in operation since 1989 in Trenton, NJ Lenox Headquarters is locater in Bristol, PA Lenox, Inc., is the oldest and most famous manufacturer of fine china in the United States.

History of Pottery

Pottery is the oldest known human handicraft, dating back 10,000 years to the Neolithic period. Pottery was hand-built, fired in bonfires and served the purpose of carrying grains, water and other liquids, as well as storing grains and seeds. They began to use pots for cooking ,serving and for eating their food .

Joining Techniques

Score - Scratching the edge of clay before joining them Slip - A fluid suspension of clay in water used in joining clay pieces and for surface decoration Bond - A mix made from clay slip of the same type of clay as the clay piece.

Stoneware

Stoneware clays have an absorption factor of about 2 to 5 percent, and are usually fired to temperatures ranging from 2100 degrees to 2372 degrees F (cone 3-cone 11*). As one might guess, stoneware clays are so named because the fired wares exhibit stone-like characteristics: a hard, dense surface with often variegated color. Stoneware usually bonds well with its glazes, and should be completely leak-proof after firing to maturity. It is tough and forgiving during throwing and firing stages, and is often used for industrial ceramics. Fired stoneware can yield pleasing colors ranging from buff or light gray to brown or dark gray. Because of its hard, tight qualities, this clay is an excellent choice for functional applications, especially dinnerware. The higher the maturing temperature of the stoneware, the more durable the product. Glaze: -°©‐ A liquid suspension of finely ground materials that is applied by brushing, dipping, pouring, sponging, or spraying the surface of a bisque fired ceramic piece. Once done the piece needs to be fired to the temperature at which the glaze ingredients will melt together to form a glassy surface coating. Glazing the surface makes it water tight, adds color, and creates a functional piece you can eat out of. All of the glazed you will be using in Ceramics are lead-°©‐free. Glaze A liquid suspension of finely ground minerals which is applied by brushing, pouring, or spraying on the surface of bisque‑fired ceramic ware. After drying the war is fired to the temperature at which the glaze ingredients will melt together to form a glassy surface coating. Made from clay mixed with a fusible stone Fired at temperatures ranging from 1, 350 to 2,190 degrees F Stone-like characteristics: a hard, dense surface with often variegated color. Gray to tan or brown when moist Fired stoneware colors ranging from buff or light gray to brown or dark gray. Durable Used for dishes, oven to table serving dishes, and decorative pieces

China

The bone ash that is used in bone china is made from cattle bones that have a lower iron content. Soft paste (artificial porcelain) - Made by mixing clay and fused mixture of glass and enamel called glass frit. It is not stable when firing and compared to hard paste porcelain it is not as durable. Hard paste porcelain - Made from kaolin and feldspar. Similar to original Chinese china. Made from a fine, white clay called Kaolin (silicate of alumina) and China Stone Completely Vitrified Fires between 2,280 to 2,550 degrees F Called Porcelain in Europe and China in United States and England Major producers are in European countries, Japan, and United States. Bone china is stronger and more translucent than the basic porcelain and "fine" varieties. Two primary types of Porcelain: Soft paste porcelain and Hard paste porcelain It is expensive Thin and delicate in appearance Used to make fine dinnerware, figurines, and other decorative objects

Ceramics

are also used to describe items made from clay.

Tools

mainly used to shape clay. Hands, Potter's Wheel, Modeling Tools, Loop Tools, Rib, Sponge, Wire Clay Cutter

Clay

moist, sticky dirt (mud) composed of fine-grained minerals, which can be shaped when wet and hardened when dried or heated

Pottery

refers to all articles that are made from clay. This includes earthenware, stoneware, china and bone china. It is also referred to as a type of earthenware made from crude, porous clay.

Coil Construction

Coils are long, snake-like ropes of clay that are used in making pottery. It involves building the walls of a form with a series of coils into the required shape. The surface can either remain coil-textured or they can be smoothed.

Clay Shaping Methods

Hand Building Pinch Pot Coil Construction Slab Construction Wheel Throwing Slip Casting

Pinch Pot

Pinching is a pottery technique fundamental to manipulating clay. Making a pinch pot consists of pressing the thumb into a ball of clay, and drawing the clay out into a pot by repeatedly squeezing the clay between the thumb and fingers.

Environmental Impact - Lead-glazed Pottery

Pottery made outside of the US may contain lead Foods or drinks cooked or stored in lead-glazed pottery can poison the family The bean pots found in many Hispanic homes sometimes have high levels of lead

Slip Casting

Slip: a liquid mixture of clay and water

Decorating Methods

Underglaze: Decoration added to greenware before bisque firing Overglaze: Applied as accents on top of already glazed and fired pieces, then fired again In-the-clay: Add to the clay while it is still wet. In-the-glaze: Applied over the underglaze.

Stages of Clay

Wet clay: soft/plastic clay Leather hard (greenware): clay is dry enough to maintain form and wet enough to be smoothed, carved, and added to Bone dry (greenware): clay has dried as much as possible before first firing and is extremely brittle Bisque: first firing where all remaining water molecules are released from the clay transforming it into ceramic (Why are air bubbles dangerous during a bisque fire?) Glazed: second firing where glaze has melted into the ceramic surface making it non-porous

Kiln

a specially designed oven capable of reaching temperatures over 2000° F (can be electric, gas, or wood-fired)