Panel

A panel in painting is a rigid support or surface for applying paint, as opposed to flexible stretched canvas. The most common historically was the wooden panel: a prepared board of oak, poplar, lime or another wood, covered with a gesso ground that gave a smooth white surface for tempera or oil. Wood provided a strong, stable base for fine and detailed work, so most easel pictures and altarpieces before the sixteenth century, as well as icons, were executed on panels. With the spread of canvas in Venice and Northern Europe, the panel gave way to it as the principal material because of canvas's lightness, cheapness and suitability for large formats, yet the panel never disappeared entirely. Wooden panels had a drawback — cracking and warping with changes in humidity — so conservators pay them particular attention. In the twentieth century artists returned to rigid supports, using plywood, hardboard, masonite and modern composite panels, which hold impasto well and do not deform. The term "panel" is also used for the individual parts of a polyptych and for wall panels.