One cap of potassium polyacrylate powder (aka “dehydrated gel”) is placed in an opaque 9 oz. cup. Water is added to the cup until it is almost half full. As the gel absorbs the water it expands rapidly inside the cup forming a perfect mold of the inside. When the cup is tipped over it appears as if the water has disappeared. This chemical is reusable: let it dry out, store it, and pull it out again next year.
Demo Pack includes 7/8-oz. Dehydrated Gel, 9-oz. opaque cup, tart pan $3.95
Study Group Pack includes 4 7/8-oz Dehydrated Gel, 4 9-oz opaque cups, 4 tart pans $12.95
Classroom Pack includes 10 7/8-oz. Dehydrated Gel, 30 9-oz. opaque cups, 10 tart pans $26.95