Subtractive Sculpture

Our last big project of the year is plaster carving. Plaster is our form of imitation rock. Rock is hard to carve and takes a long time. Plaster is a little easier, but still takes a great deal of patience before you can see the image your imagined.

Students begin by making a solid plaster form. Some have decided to go organic, and have poured plaster into a baggie and allowed it to dry into an amorphic shape. Others have poured plaster into cups, creating blocks of plaster similar to blocks of stone that would be bought from quarries

Student are using plastic knives to carve the plaster. But in order to do this, they must keep the plaster somewhat wet. We spritz the plaster with water to make the carving easier, and keep them in sealed plastic bags so the moisture doesn't escape.

They must design their carvings carefully. If a part is too thin, it will break off. Arms must be connected to the bodies and thin legs cannot hold a heavy sculpture. They need to think of how they can compact a sculpture so that it can be carved easily from one solid form. For example, making a sleeping cat curled up is much easier than trying to carve a cat standing on four legs.

Sculptures can be polished to a high shine with butchers wax, or made shiny by rubbing layers of milk into the plaster with a rag.