Rock Molds are durable, flexible, re-usable and well-detailed. They present the scenery modeler with value and versatility. Use Lightweight Hydrocal to cast small boulders, rock outcroppings, top rocks for fields and creeks, or entire rock faces. Plaster castings release easily and completely and can be attached with Foam Tack Glue or Scenic Glue. Color with Earth Colors Liquid Pigments. Purchase the Scenery Manual for additional information on how to use the Landscaping System. Use this mold to make rocks for anywhere on your layout.