The Addition and Subtraction Methods of Sculpting

by Nora Zavalczki
Some stone sculptures are obtained through subtraction.

Some stone sculptures are obtained through subtraction.

Hemera Technologies/ Images

Sculptors create their sculptures using materials such as clay, plaster, stone, bone, wood, papier-mache or metals. Addition and subtraction are two methods used to execute handbuilt sculptures. While an artist may use a single technique, such as subtraction, to create a sculpture, addition and subtraction are typically both employed in the making of a statue or sculptural piece.

Addition in Sculpture

Addition is a technique employed when working with soft, malleable materials such as clay, polymer clay or papier-mache. The artist prepares an armature, which is a wire support used as a skeleton for the sculpture, then forms the piece according to the desired shape by adding material to the armature. In some cases, the method of subtraction is also employed to remove excess material.

Subtraction in Sculpture

Subtraction is a technique that involves carving a solid block of stone, wood, bone, plaster or clay to remove material and obtain the desired shape. In the initial phases of sculpting, the artist sketches the shape and size of the sculpture on the block of material and removes large parts of the block. Next the sculptor creates finer details by using smaller, precision tools. Sanding is also a means of subtraction; artists use sandpaper to remove small imperfections that remain on the surface of the sculpture.

Necessary Tools

Most commonly, in addition, material is added using the hands or a palette knife. When using the subtraction technique, the artist chooses her tools according to the materials used; if the material is wood, for example, the sculptor uses a chainsaw or a circular saw to model the piece, then adds details with tools like chisels, gauges and carving knives. The sculptor uses a chisel and hammer to carve into stone, bone, a solid block of plaster, wood or ivory. Sculptors use flat chisels to remove large amounts of material from a solid block, while tooth and point chisels help create finer shapes and textures. For details and precision carving in soft materials the artist employs modeling tools, needle tools and wire loops.

Other Sculpting Techniques

Other sculpting techniques include modeling and casting. Modeling involves shaping a malleable material such as clay or papier-mache, while casting is a technique that employs a mold and and a liquid material such as plaster or molten metals. The artist pours the liquid material into the mold and allows the piece to harden into its shape. The piece can be replicated several times when using a mold.

Photo Credits

  • Hemera Technologies/ Images