General Terms and lingo
Wedge – the process used to remove any air pockets from the clay prior to modeling.
Green Ware – Anything stage of clay that hasn’t been fired yet.
Stages of Dryness - When speaking of clay, we refer to three basic stages of dryness: wet, leather hard and bone dry. They are self-explanatory.
Leather hard – this is the point at which the clay is no longer workable but not yet fired/bisque but still looks wet.
Wheel and throwing terms:
Opening (making a centered hollow into the solid ball of clay),
Flooring, (making the flat or rounded bottom inside the pot),
Throwing, pulling, lifting (drawing up and shaping the walls to an even thickness),
Trimming- Removing extra clay from around base or other
Mouth -The opening at the top of a vase.
Neck -The (usually) narrower part that leads from the body of the vase to the mouth.
Body -This is the main part of the vase. It is usually the largest part.
Foot -This is the part of the vase that meets the floor.
Terms associated with the glazing process
Basecoat: Generally an all over coat of color on bisque on top of which detailed decorating is done.
Gloss (G): A shiny, glass-like finish.
Semi-Matt (SM): A satin-like surface which has a slight sheen to it.
Semi-Opaque (SO): Colors which generally allow only dark colors to show through.
Semi-Transparent (ST): Slightly colored and/or speckled colors which allow most colors to show through with only slight distortions.
Sgraffito -Sgraffito is a decorating technique developed centuries ago. In its simplest embodiment, leather-hard clay is coated with an engobe or slip of contrasting color and then a pattern or picture is added by carving through or scraping off the slip to reveal the clay underneath. Example of an Asian jar decorated with sgraffito. Example of Mexican ceramics decorated with sgraffito.
Wax Resist -In this decorative technique, patterns or designs are created by brushing a wax medium over an area of clay, slip, or glaze to resist the final glaze application when the wax is dry.
Slip Trailing -Slip trailing is another decoration method. Slip liquid clay) is applied to the green ware through a tube or nozzle, much like icing a cake. See a demonstration here. Example of a casserole dish decorated with slip trailing.
Terms for firing or vitrifying the clay
Kiln- The furnace in which ceramics are fired. Kilns can be electric, natural gas, wood, coal, fuel oil or propane. Materials used to heat the kiln can affect the work: wood ash can build up on the surfaces of a piece and form a glaze at high temperatures.
Fire – the process by which the clay is hardened
Kiln Furniture: The series of posts, stilts, and shelves on which the ceramic ware rests in order to take full advantage of the interior space of the kiln.
Bisque – the first firing to begging the hardening process also used to fire and secure under glazes on the pottery
Under glazes – Slips that are painted on before final firing either green or bisque
Glaze Firing- The second or higher temperature firing to finish the process
Glaze – color applied to clay after the first (bisque) firing
Oxidation- (Compare to Reduction) A firing atmosphere with ample oxygen. An electric kiln always gives an oxidizing fire..
Reduction- (Compare to Oxidation) A firing atmosphere (like a wood or gas firing), with inadequate oxygen and large amounts of carbon (smoke or unburned fuel).
Raku- Pottery is fired normally but removed when it is red hot and the glaze is molten. It is then usually placed in a bed of combustible materials and covered, creating intense reduction resulting in irregular surfaces and colors.
Cone (pyrometric cone): A ceramic material that is designed to melt at the proper time and temperature in the kiln. Also used as a scale to determine how to mix a clay body.
Types of clay and Clay Bodies
Stoneware- A high-fire clay. Stoneware is waterproof even without glaze; the resulting ware is sturdier than earthenware.
Terra cotta- A brownish-orange earthenware clay body commonly used for ceramic sculpture.
Raku- Pottery is fired normally but removed when it is red hot and the glaze is molten. It is then usually placed in a bed of combustible materials and covered, creating intense reduction resulting in irregular surfaces and colors.
Porcelain- True porcelain was being made in China and Korea around 960 AD. Porcelain is a combination of kaolin (pure, white, primary clay), silica and feldspar. A unique aspect of porcelain is that it can be worked as clay, but when fired properly reaches a state similar to glass. Primary qualities of porcelain are translucency and whiteness. In the 17th Century, English potters invented Bone China to compete with the porcelain being imported into Europe.
Slip- A fine, liquid form of clay (at times, stained or colored) applied to the surface of a vessel prior to firing. Slip fills in pores and gives uniform color. Slips are also used a gluing agent for joining pieces of clay together. This is more common in hand building projects.
Terms used in Hand Building
Hand building - This term refers to the one of several techniques of building pots using the only the hands and simple tools rather than the potters wheel. The term used for creating pottery using the potter's wheel is "throwing".
Score and Slip - Score and slip refers to a method of joining two pieces of clay together. First, score the clay; this means that you make scratches in the surfaces that will be sticking together. Then you slip it; that is you wet the surface with some slip, using it like glue. Next, you press the two pieces together. It is very important to always score and slip clay that is leather hard, if you do not, the pieces will likely pop apart when they are fired.
Slip Joining – the process used to join two pieces of clay by moistening both pieces with water, making a slip, then pressing firmly together and smoothing the join
Pinch - "Pinch" in ceramics is a method of shaping clay by inserting the thumb of one hand into the clay and lightly pinching with the thumb and fingers while slowly rotating the ball in the palm of the other hand. [See resources for links to tutorials on how to create. See the Assignment 2 page for examples of pinch pots.] Pots made in this manner are called "pinch pots".
Coil - This is the technique of building ceramic forms by rolling out coils, or ropes, of clay and joining them together with the fingers or a tool. Extruders or extruded coils also fit this general term.
Coil method- One of the oldest ways of forming pottery. Long strands of clay which are laid on top of each other and joined through blending coil to coil. Coil pieces can be almost any shape and any size.
Molding - In this technique, flat slabs of clay are pressed into molds in order to create various shapes or forms.
Armature- A structure that is used as a skeleton or frame work for material to be added to create a finished form
Stamping - This is the technique of pressing forms into the clay to get decorative effects
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