High Strength 20 Plaster for Scenery, Dioramas, Dentistry and Mold Casting 5 lb Pack Resealable Bag Great for Model Railroads & Gaming by Capital Ceramics High Strength 20 Plaster for Scenery Dioramas and Casting Quick setting, lightweight white plaster in water resistant bag. Ideal for patterns, figurines, commercial casts, and sculpture. Can be used for making outer or mother molds, and it is not recommended for outdoor use. Full strength limestone high density plaster, not cut with cheap plaster fillers Designed for strength and casting detail. High Strength 20 is 20% to 30% harder than Plaster of Paris and works much better in mixing, pouring, and setting. Accepts liquid or crystal pigment colors and stains