Vinyl Siding is made from a PVC (polyvinyl chloride) plastic resin that is heated until molten and then extruded into sheets. The sheets are then embossed with a brushed or wood-grain pattern that provides textural interest and dulls PVC’s inherently shiny and synthetic-looking surface. While still hot, the sheets are formed into siding panel profiles. Manufacturers use additives to improve impact resistance, and to prevent ultraviolet damage and color fading. Color pigments are mixed with the vinyl resin before the plastic is extruded, so vinyl color is full depth, or nearly so.