A method of shaping plastic sheet over a solid relief pattern. The plastic is heated until it is pliable, and when a vacuum is created under the form, the plastic is drawn down onto the pattern like a skin.

An element of art that describes the lightness or darkness of a color. Value is an especially important element in works of art when color is absent. This is particularly likely with drawings, woodcuts, lithographs, and photographs. It is also true with most sculpture and architecture.

A series of spaces filled with the tints and shades of one color, starting with white or the lightest tint on one end, and gradually changing into the darkest shade or black on the other. An example of a value scale can be seen in the article on value.

In linear perspective, the place on the horizon where parallel lines seem to meet.

A protective transparent finish applied in a liquid state to a surface. One example is glair-- a varnish for tempera paints.

See Also:  acrylic paint,  oil paint,  medium,  pigment,  polymer,  shellac

A stone roof shaped in a variation of an arch. There are several types of vaults, including the barrel, corbel, cross, and groin vaults.

Example: Durham Cathedral, England, begun c. 1093 is built with pier-vaults.

Something that moves things around. In the visual arts, usually the liquid, usually water or oil, that is mixed with pigments to make paints, dyes, and inks.

Fine parchment, originally calf-skin, used traditionally for manuscript.

The thin slice of a material-- often of a rare and expensive material-- applied, generally with an adhesive, but also (and sometimes only) with pins, to a surface of a humbler material. Ebony, rosewood, tulipwood and other exotic woods are more often used as veneers in furniture-making than they are used in a solid form. Most wood veneer is sliced rather than sawn, and taken from a log in a continuously spiraling (voluting) cut, and then flattened. Because of concern that such veneer may be more likely to curl away from its placement, some feel that flatly sawn veneer is preferable. Sawn veneer however, because the saw destroys as much wood as the veneer it produces, is much more expensive. Brass, copper, ivory, mother-of-pearl, pewter, and tortoiseshell can also be used and are often combined with such woods. Semi-precious stones such as lapis lazuli and malachite (also used for inlay) are sometimes employed as a veneer, as are the more showy types of calcite alabaster. Veneering is more easily achieved on a flat surface, but thin slices of wood can be bent, for example into the hollow of a molding. Stone cannot be bent, so its veneering on curved or complex forms is particularly difficult. Also see cladding, intarsia, laminate, marquetry, mosaic, and parquet.

Canada balsam, an oily resin or balsam obtained from conifers.

See Also:  turpentine

The highest point; the apex or summit. The point at which the sides of an angle intersect. The point on a triangle or pyramid opposite to and farthest away from its base. A point on a polyhedron common to three or more sides. The plural form can be either vertexes or vertices.

Going straight up and down; the opposite of horizontal. A vertical sculpture is taller than it is wide. Portraits are conventionally vertical in their orientation, while landscapes are most often horizontal. Any orientation neither vertical nor horizontal is diagonal.

A hollow container, such as a cup, bowl, or vase, for holding something. Its parts include its foot or base, its walls and opening, its rim or lip, and sometimes: shoulders, neck, lid, handle, etc.

A small window cut in a piece of paper or card that shows what will be in a picture's composition. Or, a window seen through a camera which shows an approximation of a picture the camera would photograph Viewfinders.

The relative resistance of a liquid to stirring or movement, and its stickiness.

To change materials into glass or a glass-like substance through heat fusion. This is the action of a kiln heating ceramic clay and glazes, for instance. A curious example: lightning striking a metal rod partly buried in sand will cause all the sand within a certain distance from the rod to vitrify.

See Also:  ceramics,  firing,  glass

Containing no matter; empty, negative space.

Rapidly evaporating (as are many solvents). Or, tending to vary often or widely; inconstant. Or, capable of quickly becoming violent. (pr. vah"leh-tl')

Refers to the space within a form. Thus, in architecture, volume refers to the space within a building.