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 surface or into a silicone mold. The brushed clay has minimal to no slumping at less than a ¼” thickness.  

Burn (Clay Product): When clay is overheated it can smoke, bubble, discolor, give off fumes, harden, and display the appearance of granules. Burned clay is unusable clay that cannot be reconstituted to its original state.

Burn (Skin Burn): Skin tissue damage brought on by heat, chemicals, electricity, radiation, or the sun.

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 at which a clay is melted into liquid state and poured into a mold to create an accurate clay casting that can be further shaped.

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.

Dwell/Dwelling: A Slush-Casting process where a hot liquid clay is given time to temporarily rest (dwell) without moving to partially cool against a mold surface. By dwelling, a thicker clay layer is cast inside a mold.

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 (also Maximum Temperature): The hottest temperature a clay cannot exceed before overheating, bubbling, scorching, or burning. 

Note: All Chavant Clays can soften with heat. Some clays can be further softened to be troweled on surfaces, brushed on surfaces and molds, or liquified to pour into silicone molds to create clay castings.

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.

Rotational Casting: A casting process where a mold is filled with a liquid material (liquid resin, hot liquid clay, plaster, or wax) and turned with Rotational Casting Machine to create a reproduction with a smooth hollow interior and even thickness.

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.

Separate: When a clay is heated and the liquid oils and dry components of a clay visibly separate and need to be reconstituted/remixed together.

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.

Slush Casting: A rotational casting process where a mold is turned by hand after a casting material (example: hot liquid clay) is poured into the mold. The process is typically repeated in layers to create a hollow reproduction.

Softening Temperature: The temperature at which a clay reaches its softest state before the application of heat causes the clay to overheat, scorch, or burn. 

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 softened clay can be spread onto a vertical surface (armature or support structure) with a trowel or similar tool. The troweled clay 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.