Capstock Color Selection Superior Seal Window colors are achieved through a revolutionary process called Capstocking.  Unlike laminated vinyl color adhesives that are glued on to the exterior surfaces, or paint that is applied to the surface of the vinyl, capstocking is a superior process.  Capstock insures a homogenized product where the colored vinyl and the white vinyl are permanently bonded together during the extrusion process.  This co-extruded Capstock is the highest quality of vinyl that money can buy.  It has the greatest amount of ultraviolet protection and is very flexible, providing unprecedented protection against the sun's damaging rays.  This technology produces a far superior color system than any other process on the market today.  While other color processes can delaminate or be easily scratched, our co-extruded colors will stand the test of time.