Celastic

Description

[Atlas Orthopedic International, Inc.] A non-woven, Polystyrene -impregnated fabric that becomes moldable when activated with solvent (Acetone or MEK). When Celastic® is dry, it forms a stiff, lightweight shell that is able to hold its shape at large scale. The versatile material is used by model makers, costume and stage designers, taxidermists, and float makers to produce and maintain shapes. Celastic® is also used by orthopedists and shoemakers for lightweight shoe and orthotic support. In museums, it has been used for reinforcing joins on fragmentary archaeological vessels and as shape supports for fabric.

The original Celastic material, trademarked in 1926, was impregnated with Cellulose nitrate. It was used widely in the theatrical industry from the 1930s-80s for prop-making (Eric Hart). A reformulated version, sold since 2005, does not contain toxic materials. Alternatives developed in recent years include Varaform, Wonderflex (heat-activated thermoplastic), and Fosshape (heat-activated thermoplastic).

Applications

Sculpting models and masks
Toe box, toe puffs, heel counters
Taxidermy

Risks

CelasticWorld: SDS

Physical and Chemical Properties

Celastic® is soluble in acetone and MEK
Insoluble in water

Working Properties

Can be cut to size with scissors
Becomes moldable when immersed in solvent.
Working time with acetone is less than MEK; acetone activated material has less tack during working period
The hard, rigid form may be drilled, sanded and painted.

Forms and Sizes

Sheets (29" x 54") in thicknesses from 0.8-2.0 mm
Rolls (54" x 120 feet) in thicknesses from 0.8-1.2 mm
Rolls (54" x 95 feet) in thicknesses from 1.5-2.0 mm

Resources and Citations

CelasticWorld website: celasticworld.com
Atlas Orthopedic International, Inc.; parent company of Celasticworld; and tradename holder of Celastic®
Bob Holkan, Atlas International, Submitted information, July 2024.
Eric Hart, Prop Agenda: Celastic
Chris White, Arizona State Museum, Submitted information, March 2008.