Eyewitness Perfect Cast Casting Kits combine creativity, discovery, and learning in one exciting artistic journey. First, follow the instructions to make a mold of a simple item of your choice using the Alginate Molding Material. Next mix the Perfect Cast Casting Material and pour it into the mold that you have created. While it sets read all about what its like to be a paleontologist creating molds and plaster casts of fossils in the illustrated booklet.