Plaster

For making molds, various plaster products include Ultracal 30 for durable, heat-resistant, and long-working-time molds, Hydrocal for strong, moisture-wicking, detailed casts, and Hydrostone for very strong, fast-setting production pieces, as well as fast setting plasters like 20 Minute Plaster. The best choice depends on the desired strength, working time, and the casting material being used.