Sculpture

119 flashcards by MentisLibrary

How sculpture is made and how it developed: carving, modeling, casting and assemblage, the terms of the trade, landmark works from prehistory to the present, and the problems of public and contemporary practice.

What are the four basic ways of making a sculpture?

Carving, which removes material; modeling, which adds it; casting, which replaces one material with another inside a mold; and constructing or assembling, which joins parts together.

Subtractive vs additive process

Subtractive work, carving, removes material and cannot be undone, so the sculptor works from the outside in and leaves a margin. Additive work, modeling, builds up and can be corrected at any point.

Why is marble the classic carving stone?

It is a metamorphosed limestone, fine grained, uniform enough to carve in any direction, and light passes a few millimeters into the surface before scattering, which makes carved flesh look soft.

What is the standard bronze alloy for sculpture?

Copper with roughly ten percent tin, though modern foundries often use silicon bronze, which flows well and welds cleanly. The alloy is far stronger in tension than any stone.

Why do Roman marble copies of Greek bronzes have tree stumps and struts?

Marble is strong in compression and weak in tension, so an unsupported limb or a figure balanced on one foot would snap under its own weight. The bronze original needed no such prop.

Patina

The surface color of a bronze, either the natural corrosion of decades or a chemistry the foundry applies with heat and brushed solutions to produce browns, greens or blacks.

Was ancient Greek sculpture white?

No. Greek and Roman marbles were painted in strong colors, with gilding, inlaid eyes and metal attachments. The pigment weathered off, and the bare stone was then mistaken for the intended effect.

Polychromy

Sculpture that is painted, gilded or inlaid rather than left the color of its material. It was normal in Egypt, Greece, Rome, medieval Europe and most of the world outside modernism.

Which woods are favored for carving, and why?

Close-grained and stable woods that hold detail: limewood and pear in northern Europe, oak for larger work, cedar and cypress where rot resistance matters. Grain direction governs everything.

Terracotta

Fired clay, literally baked earth. It is cheap, quick to model and permanent once fired, but it shrinks as it dries and fires, and it must be hollow or thin walled or it will explode in the kiln.

What is grog, and why is it added to clay?

Ground previously fired clay mixed into the body. It opens the clay, reduces shrinkage and cracking as the piece dries, and helps a thick wall survive firing.

Greenware, leather-hard, bisque

Three states of a clay piece: leather-hard clay is stiff enough to carve and join but still damp; greenware is bone dry and extremely fragile; bisque is the result of the first firing, porous and durable.

Why is plaster central to a sculptor's studio?

Plaster of Paris sets fast, records fine detail and is cheap, so it serves for molds, for durable copies of clay models, for enlargements and for the version sent to the foundry or the carver.

Armature

The internal skeleton, usually wire, pipe or wood, that supports modeling material while it is soft. For clay meant for firing it must be removable, since clay shrinks onto anything rigid and cracks.

What is lost-wax casting?

A wax model is coated in a heat-proof investment, the wax is melted out to leave a void, molten metal is poured into it, and the mold is broken away. The wax is destroyed every time, hence the name.

Direct vs indirect lost-wax casting

In the direct method the original wax is melted out and lost, so the result is unique. In the indirect method a mold is taken from the model first and wax copies are made in it, so an edition is possible.

Why are bronze sculptures hollow?

Because metal is heavy and expensive, and a thick solid casting cools unevenly and cracks. The wax is built as a shell over a refractory core, so the metal ends up a few millimeters thick.

What are chaplets, and what do they do?

Small metal pins driven through the wax to hold the inner core in exact position after the wax melts out, so the metal wall stays an even thickness. They are cut off and chased away afterward.

Sprue, gate, riser, vent

The wax plumbing added around a model before investment: the sprue is the main channel that carries metal down, gates feed it into the piece, risers hold a reservoir that feeds shrinkage, and vents let gas escape.

What is chasing?

Finishing the raw casting: sawing off the sprues, welding the separately cast sections together, grinding the seams, and re-cutting the surface detail with punches and chisels so the joins vanish.

Waste mold vs piece mold

A waste mold is broken off the cast and can be used only once, which suits a one-off plaster. A piece mold is built in interlocking sections that separate cleanly, so it can be reused for an edition.

Sand casting

Molten metal poured into a mold rammed up in bonded sand around a pattern, in two or more flask sections. It is fast and cheap, gives a slightly grainy surface, and does not need a wax.

Slip casting

Liquid clay poured into an absorbent plaster mold, which draws water from the clay against its wall until a shell has formed; the rest is poured out. It gives thin, even, repeatable ceramic forms.

What is direct carving?

Cutting into the block without a finished model to copy, letting the material's shape and grain lead the form. Modernists adopted it as an ethical position against the workshop copying system.

Truth to materials

The modernist principle that stone should look like stone and wood like wood, so the sculptor works with grain, hardness and color rather than disguising them as flesh or cloth.

What is a pointing machine?

A frame of adjustable arms that transfers measured points from a finished plaster model to a rough block, so an assistant can cut a marble to within a few millimeters of the surface before the master touches it.

Which chisels does a stone carver use, and in what order?

The point or punch first, to knock off mass; then the tooth or claw chisel to bring the surface down evenly; then flat chisels to shape; then rasps, rifflers and abrasives to finish.

Non-finito

Sculpture deliberately or unavoidably left unfinished, with figures still half embedded in the raw block, which reads as struggle and emergence.

How does welding change what sculpture can be?

It joins metal by melting it, so a sculptor can draw in space with rod and sheet without any mold, foundry or carving. The result is open, linear and weightless-looking rather than mass-based.

Assemblage

Sculpture built from existing objects and fragments rather than shaped material, so the parts keep their old identities while forming a new one.