Glossary of Terms Common to Chavant Clays

Adhesion - The ability for a product to stick to other, non-similar, materials.

Aging - Clay has a life cycle that can sometimes be accelerated. Aging can describe physical changes in clay over time.

Armature - The substructure that supports a clay model.

Billet - A billet, offered as blocks or cylinders, is the finished extruded form that the clay is packaged in. The approximate size of the block billet forms are 1 pound blocks, 1" x 4" x 4"; 2 pound blocks, 2 ¾" x 2 ¾" x 5½"; 5 pound blocks, 5 ¾" x 5 ¾" x 6; and 10 pound blocks 5 ¾" x 5 ¾" x 12". The approximate size of the cylinder billets are 2 ½" x 12" (2 ½ pounds each); 3" x 8" (3 pounds each); and 3" x 16" (6 pounds each).

Brushable Temperature:  The temperature at which a softened clay can be brushed on a vertical armature surface or into a silicone mold, with minimal to no slumping at less than a ¼” thickness.  

Burning Clay - Used when describing overheating clay in a warming device or by the exothermic reaction created by some mold making materials.

Cast - The positive form that reproduces the negative shape of a mold taken from the positive clay pattern. The cast will be an exact duplicate of the clay model.

Castable Temperature: The temperature a clay is melted into liquid state and can be poured into a mold to reproduce an accurate clay casting that can be further shaped when cooled. 

Clay Body - A term used to describe different clay formulas with different characteristics.

Cohesion - The ability for a product to stick to itself or similar materials.

Consistency - The uniform or homogenous properties within an individual clay body. Also used to compare similar qualities from production batch to production batch.

DeAired - A process of clay extrusion. By running a clay through the DeAiring process, a clay becomes smoother and more homogenous. This procedure is a vigorous mixing cycle that reduces ingredient particle size and removes entrapped air, creating a finished product that has a somewhat higher density.

Extrusion - Process of forcing clay through a pre-cut die shape.

Filler - Inert material mixed together with other clay ingredients to create the clay body base.

Fine Art Clay - Clay used in the Fine Arts field for sculpture.

Firmness - A value, from 1 - 10, associated to the room temperature hardness of clay, with "1" being the softest clay and "10" being the hardest clay.

Industrial Design Clay - (Hard Styling Clay) Clay developed for use by Industrial or Product designers. Has the ability to hold exacting detail and to be polished to a glasslike finish. Template shapes can be pulled through Industrial Design clay to create an accurately reproduced, dimensionally stable shape. Industrial Clays can also be milled.

Length - The ability of a clay body to stretch, bend or twist. If you were to roll clay into a pencil shape and stretch it, sometimes it will fracture, other times it will pull apart and eventually split in a "taffy" like point. Greater length means more flexibility.

Max Temperature: The temperature a clay cannot exceed before overheating, bubbling, or burning.

Melting point - The temperature where a clay body becomes fluid.

Mold Making - The process of reproducing a negative form from a positive shape of clay. Flexible mold making materials include urethane, silicone, latex and polysulfide rubbers. Rigid mold making materials include plaster and fiberglass.

Oxidation - A reaction between oxygen and the surface of the clay, typically noticed as a hardening of the immediate surface of the clay. Higher temperatures, especially in clay ovens often accelerate oxidation.

Penetration - The value, representing the distance a needle will push into clay at various temperatures. Chavant will refer to the Firmness of a clay body.

Plasteline, Plastilina, Plasticine - A generic term to identify oil based sculpting clay from other types of clay.

Plasticizer - Lubricant in clay to assist in moisture retention and flexibility.

Release Agents - Products used to prevent mold making materials from sticking to clay models or to prevent cast parts from sticking in the mold.

SDS - Safety Data Sheet

Sealers - Products used to incorporate a protective film (Barrier) over the clay, which will prevent a mold making material or other product, such as a paint, from coming into direct contact with the clay. Sealers can include shellac, lacquer or clear acrylic finishes.

Shelf Life - Period of time before a product will lose some of its useful characteristics.

Slick - A tool with rounded edges, made of polycarbonate or lexan, used to smooth the surface of a Hard Styling Clay model.

Softening Temperature: The temperature at which a clay reaches its softest state before the application of heat causes the clay to overheat and burn. Some clays can be further softened to be troweled on surfaces, brushed on surfaces or in molds, or poured into silicone molds to create clay castings.

Splash Mold - A mold taken from only an isolated portion of a model.

Sulfur Based - Sulfur is a non-toxic filler used in many modeling clays. It provides a silky, unique feel to the clay, is readily available and its price is reasonably stable. Sulfur based sculpting clays produced by Chavant include Professional Plasteline and DaVinci. Industrial clays (often used by sculptors) which contain sulfur include CM-50, J-525, and CM-70.

Sulfur Free - A clay body absent of sulfur. Sulfur Free clays produced by Chavant include NSP, Le Beau Touché, Clayette, Monumelt, Prima, Jolly King, Castilene, Fill-It, Autostyle and Y2 Klay. 

Surface Development - Clay surfaces can be modified by using various tools or fluid materials. Polished Lexan slicks can be used for highlighting Hard Styling Clays and many solvents can be used to smooth the Fine

Surface Plate - A perfectly level working area often with precisely measured grid markings used for coordinate measuring.

Template - A predetermined shape cut into various materials including aluminum, Masonite or Lexan, which is pulled through the clay to transfer the shape into the clay.

Trowelable Temperature: The temperature at which a clay can be softened with heat and spread onto a vertical armature surface with a trowel or similar tool. Has minimal to no slumping at ¼” thickness.  

Warming techniques - Any method of heating clay to create a softer consistency. Most Plasteline is wax based therefore warmer temperatures will soften the wax.  The typical temperature range for warming fine arts clays is 110° – 145°F and for industrial design clays is 130° – 160°F.