Lightweight Hydrocal plaster has been specially formulated for terrain model builders. It is half the weight of Hydrocal plaster, goes twice as far and is a tough, quick-setting product. Create your own castings or use it to cast rocks or create your own castings. Create a hard shell terrain, use as an adhesive to attach or fill in around castings or use it to strengthen existing terrain. Stain with Earth Colors™ Liquid Pigment.