Convex or concave? Part of the fun of using plaster waste molds as part of my process comes from this optical illusion. This torso is actually the inside of a mold. Look carefully and you'll see that the sides of torso are closer to the camera than the belly button. The pictures below are different views of the same section of the mold.
After the clay sculpture is finished, I make this plaster waste mold. It is aptly called a waste mold because it is a one time use mold and is destroyed by being chipped away from the surface of the finished casting. I use this optical illusion to help me see what the sculpture looks like. Inside the mold I can carve away material to refine the surface of the mold, achieving effects that are harder to create while working on the clay or the finished casting. I can push the forms out from the inside of the mold, to capture a vitality, like an internal blood pressure constantly keeping the flesh inflated with life.