Pilaster

A pilaster is a flattened, rectangular architectural member that projects only slightly from a wall surface, dressed to resemble a classical column complete with base, shaft and capital, but without a column's full three dimensional, load-independent presence. Pilasters occupy a spectrum between pure ornament and genuine structure: as an ornamental device a pilaster simply overlays a wall to suggest the rhythm and proportion of a colonnade without bearing significant load, while a structural pilaster is a thickened section of wall or an integrated pier that does carry load. Pilasters follow the proportional systems of whichever classical order they represent, echoing a column's base, shaft and capital, though they conventionally omit entasis, the subtle swelling curve given to freestanding column shafts. The device traces to Greek and Roman antiquity and was deliberately revived and systematised for wall architecture by the Renaissance theorist and architect Leon Battista Alberti. Pilasters commonly frame doorways, windows and bays on facades, and where two walls meet at a corner a pilaster-like corner treatment is termed a canton. The device saw a further surge in popularity during the Greek Revival and remains in occasional use in contemporary design.