The original is then coated with a barrier coat, like shellac and a separator of (wax) is applied.

There are many varieties of separators. The one that you chose is dependent on the original material and the type of rubber that will be used.

A blanket of clay approximately 1/4" is applied to the complete surface of the sculpture, (this will determine the thickness of the rubber later in the process). Keys are placed on the clay blanket as well as a pour spout and a button key. The keys will help register the rubber into the mothermold.

Metal flashing is then placed around the circumference of the clay blanket with keys. This will allow the plaster mothermold to divide into sections.

More plaster and burlap are added around the edge of the mold, which will strengthen the edge for clamping and prying apart later.