Shades for lamps are made in drum, bell, square, oval, rectangular, and novelty shapes; materials include stretched silk, parchment, which is actually oiled paper, plastic, and pleated silk. Various metals may also be used, such as decorated tin, lacquered brass, or pewter. Shades made of soft fabrics require a decorative trimming at top and bottom, which may be in the form of tailored folds (bound by ribbon or shirred), braid, or gimp. If the shade is decorated, it should be subordinate to the design of the lamp base, although the same decorative motif may be used on both. The extent and type of design in the shade helps it to be not too prominent in the decorative scheme.
The shade for the lamp with a base shaft is made with a washer which slips over the top of the shaft, a finial being screwed down to hold the shade firm. For the single-bulb base, a metallic "harp" is used which frames the bulb and has a screw top on which the shade rests. Shades used with reflector bowls are made with a lip or notch in the supporting wires that slip over the edge of the bowl. Open-top shades are preferable except when the lamps are on low tables, so that anyone can look down into them.
Light-diffusing glass or plastic bowls hidden under the shade give pleasing results; if no diffusing element is used, shades should be deep enough, so that the bare bulbs will not be visible to anyone seated beside them. Shades should be large enough at the bottom so as not to confine all the illumination about the base of the lamp. If the lamp is to be used for reading, the shade should be wide enough to direct light on the reading plane. Suggested minimum diameters for shades are: floor lamps, 18 inches; table lamps, 16 inches; bridge lamps, 12 inches.
It is a good idea to have all the lamp shades in a room of one color, to eliminate a spotty effect, but they need not necessarily be of the same material. They should be kept .at the same eye level so as not to be disturbing. Duplicating lamp shades in a room is not recommended, as variety lends interest. A pair of distinctive lamps, however, is always a good investment. White or yellow shades give a pleasant light for living rooms, and yellow, pink, or blue for bedrooms.
Shiny black shades can be very smart, but they must be opaque; the same is true for any dark color used. The shade should be extremely simple, though the materials covering it may be as rich as desired. Trimming should be subordinated to the shape and proportions of the shade as a whole. The relation of textures between base and shade is something to be considered.
Materials for shades should be sufficiently opaque to conceal the contour of the lighted bulb. Glare can be caused by white or very light shades against dark backgrounds. When white shades are necessary in the decorative scheme, the glare is easily overcome by supplying the shades with ivory or off-white linings or by using tinted bulbs.
A white-lined, dark-colored shade concentrates light in a given spot; a light shade of translucent material diffuses the light over the entire room and consequently is best for general illumination.