Vinyl composition tile (VCT) is a finished flooring material used primarily in commercial and institutional applications. Modern vinyl floor tiles and sheet flooring and versions of those products sold since the early 1980s are composed of colored polyvinyl chloride (PVC) chips formed into solid sheets of varying thicknesses (1/8" is most common) by heat and pressure. Floor tiles are cut into modular shapes such 12" x 12" squares or 12" x 24" rectangles. In installation the floor tiles or sheet flooring are applied to a smooth, leveled sub-floor using a specially formulated vinyl adhesive or tile mastic that remains pliable. In commercial applications some tiles are typically waxed and buffed using special materials and equipment.