The Making of a Sculpture using a Plaster Cast



These images show the steps taken from the initial modelling in clay of the sculpture through to the plaster cast. The plaster sculpture is refined and used as the basis to take measurements off of when enlarging to the final 3-foot  sculpture shown below.

monumental figurative sculpture of cat by ellen scobie, vancouver sculpture studio

The idea for the sculpture was first worked out in a clay with a live model in the studio. I sculpted a small figure about 6 inches high. Later I added the cat’s head and cast the sculpture in plaster.

The next step was to double the size of the sculpture, creating a figure about 12 inches high, which you see above.

Creating the Plaster Cast

The first step in creating a plaster cast is to insert metal shims to create a flange dividing the sculpture into two halves.

After plaster is poured onto one half of the sculpture, it is allowed to harden. The sculpture is turned over and plaster is poured into the other half.

When the plaster has set, the shims are removed, the mold is pried open and the clay scraped out. I try to keep the clay moist all through-out as it is much easier to remove later from the mold.

The mold needs to be cleaned thoroughly and any small holes repaired with clay. I use steel wool to polish the inside of the mold for a smooth finish. Vaseline is painted on the edges where the two halves of the mold meet each other and we brush ordinary dish soap inside the rest of the mold. This will help the plaster cast release more easily from the mold once poured.

Once cleaned and prepped, the two halves of the mold are fitted together tightly and bound with wire. Plaster is poured in through an opening at the bottom of the mold. As soon as the mold feels warm to the touch I begin to de-mold. A chisel is used to break apart the mold to release the plaster cast inside.

I love the photo of the cat-person sculpture being born! The plaster cast needs a little bit of finishing. I sanded the surface to get rid of any imperfections.

All the decisions about form and volume have been worked out in this 12 inch plaster maquette. The essence of the sculpture is now determined. I worked a lot on the face to capture the calm, serene expression and on the body to be relaxed and quiet yet still powerful.