The chief characteristics of the International style are smooth unornamented surfaces, flat roofs, usually without a ledge or coping, bands of windows, often set flush with the exterior wall, and asymmetrical composition. A complete lack of ornamentation distinguishes the International style. Horizontality, particularly on commercial buildings, is employed through alternating bands of windows and solid planes created a horizontal effect. Wood or metal casement windows are common. The style, which dates primarily from the 1930s through the 1950s, with a revival in the 1970s, also emphasizes light and shadow as opposed to color.