Pantograph - Machine used in enlarging and reducing sculpture; also known as a pointing machine.
Parting Agent - Spray liquid or paste that assists in the separation of the model from the mold or the cast from the mold.
Parting Tool - A “v” shaped wood or stone carving tool, also referred to as a veiner. Comes in different sizes with varying angles or degrees of slope.
Patina - Coloring of a sculpture in plaster, bronze, plastic, etc. with acids or pigments. Variations are countless due to the variety of color mixes. The natural bronze patina on statues is caused by oxidation and the weather.
Peeling - Occurs when the glaze does not adhere to the clay after firing. Caused by the mismatch of the clay body and glaze formula.
Percussion - Striking or hitting a stone or wood carving tool with force to make it function.
Permeable - A state such that water or moisture can pass through. A clay body is water permeable when it has not vitrified and water leaks through the piece.
pH - Used to express acidity and alkalinity on a scale from 0 to 14, 7 being neutral.
Pick - A pointed dual-sided stone carving tool used to reduce a basic geometric stone form rapidly; usually has a long handle ranging from 10 inches to 12 inches in length. Also called bush and pick.
Pickling - A cleaning process for bronze and other metals.
Piece Mold - Mold made of multiple sections for ease of construction. Generally used when severe undercuts are present.
Pietrasanta - Small town in northwestern Italy renowned for its sculpture studios and bronze foundries.
Pig - Solid volume of raw material in bulk, facilitating storage by foundries. For example, pigs of bronze.
Pin Holes - Small holes formed on a glazed piece in firing caused by incompatibility of the clay and glaze or by the firing temperature being too low. May also occur when mixing chemically activated, multiple-part rubbers.
Pink Alabaster - Common to the western United States, a light pink medium hard grade stone with minor to medium veining. Sometimes with a crystalline structure and often with iron deposits or fragmentation from dirt.
Pins - Metal or wood dowels that secure a sculpture to the base or pedestal, or hold sections of the sculpture together.
Plasteline - Generic name for oil and wax based modeling clay. See Plastilina.
Plaster of Paris - A generic term for industrial grade plaster or gypsum found in hardware stores. Not recommended for mold making, casting or sculpture, because of its softness and porosity.
Plaster Rasps - Specially designed rasps used for plaster work in sculpture. They are designed to look like a cheese grater so that dried plaster can be removed without clogging the tool.
Plaster Scrapers - Tools for plaster work specially designed to work against heavy resistance in the material. Made of high carbon steel, sometimes with wood handles.
Plaster Tools - Steel tools used in working plaster. They have flexible ends so they can flow with the material when wet.
Plasticine - Generic name for oil and wax base modeling clay. See Plastilina.
Plasticity - Resistance and smoothness of a clay body.
Plasticium - Generic name for oil and wax base modeling clay. See Plastilina.
Plastic Tools - Low cost injection-molded tools in the primary modeling shapes.
Plastilina - An oil- and wax-base non-hardening modeling material. Comes in two primary grades, professional and school. The professional grade becomes more pliable with age and is sought after by professional sculptors especially after it has been used for 20+ years. Estates have auctioned quantities of old plastilina at five times its original purchase price. Used material is refurbished by adding oil, wax, and at times clay binders. The professional grade material often contains sulfur which inhibits certain mold making materials, but causes the high quality effect. All pieces created with this material must be cast.
Pliatex - Trade name of Sculpture House, Inc. Used in mold making and with casting materials such as Pliatex Mold Rubber and Pliatex Casting Rubber.
Plug - Created on the top or sides of a mold for a pouring and for material removal access in the mold making process of larger pieces.
Pneumatic - Operated with air. Pneumatic handpieces are used in sculpture as are rotary sanders that run on forced air from a compressor.
Point - Sharp stone carving tool for quick reduction of mass material from its bulk geometric form. Sizes vary in diameter from 3/8 inch, ½ inch, and larger.
Pointing Machine - Used in duplicating a sculpture or in enlarging and reducing pieces.
Polishing - The final process, if desired, in finishing a piece of sculpture.
Polychrome - Colorful decorations on pottery created with stains or glazes.
Polymer - A chemical compound made up of repeating structural units.
Polymer Clay - Plastic modeling material that is moist when modeled and can be fired in the kitchen oven to cure and become permanent.
Polysulfide - A compound that contains sulfur atoms.
Polyurethane - Various polymers used in mold making for flexibility and as an elastomer. May also be a type of casting resin.
Pooled Glaze - Caused by a build up of glaze (an excess of liquid on ceramics or pottery) which melts when fired and pools in a settling area.
Pooling - Caused by too great a build up of glaze.
Porcelain - A fine grolegg clay formula which produces an off-white translucent fired clay at high temperatures. The finest ceramic pieces and most difficult to achieve are made of porcelain. Material may be wheel thrown or slip cast.
Porosity - The percentage of moisture absorption capability contained in a material. Term is used in ceramics and plaster working.
Porous - The ability to absorb liquid or moisture.
Portuguese Marble - A lightly veined pink marble with slight fractures and markings, with a high crystalline structure.
Posts - Devices used in kilns to hold shelves when bisque or glaze firing.
Potash - Potassium carbonate from wood ash used in pottery and ceramic glazes.
Potter - A person who makes pottery either by hand or on a kick or electric wheel.
Potter’s Wheel - A wheel, either electric or foot-powered, that enables a potter to produce pottery using a flat level rotating disc head on a circular pipe device.
Pouring - The process by which a cast is made in a mold, either hollow or solid, in plastic, bronze, or plaster, etc.
Pouring Gate - An extended section at the top of the mold that enables liquid to be poured easily into the mold without losing material.
Pressing - Laying clay in a mold to gain a positive by applying pressure and to achieve details of the mold.
Proportional Caliper - Hand held device used to calibrate exactness for enlarging and reducing sculpture. Sizes vary from 18 to 42 inches.
Puddle - Also known as pooling, a build-up of glaze due to its over-application on a ceramic or pottery piece.
Pug Mill - Mixing machine used in pottery to mix and extrude a clay formula from either dry or moist materials.
Pulverizing - Grinding a material to a given screen mesh or fineness. See Grog.
Pumice - A powder that is mixed with water for use in a last abrasive polishing.
Pumicite - A gritty volcanic ash.
Pure Beeswax - Wax extracted from bee hives. It is used to dress wood sculpture, tie dye clothes, and seal wood. Sometimes used as a direct modeling material, but because of its high cost, not often.
Pure Metal - A single non-bonding metal, without alloys.
PVA-Polyvinyl Acetate - Plastic casting resin.
PVA-Polyvinyl Alcohol - Polymerized vinyl compound condensed into a liquid state.
Pyrometer - Device that measures the temperature in a kiln for ceramic and pottery firing.