Approximately 50% of all bath fixtures sold in the U.S. are produced from gelcoat and polyester. This process involves spraying a thin coat ( i.e. 20 to 40 mils) of pure colored polyester resin (gel-coat) on to the surface of a mold. It is followed by a thick coat of a combination of a polyester resin with short fibers of glass imbedded in the resin for imparting strength. 

These resins are allowed to cure for a few hours, and then it is separated from the mold to continue the manufacturing process. Polyester resins are subject to damage by chemicals, sunlight, and impact. This product, typically referred to as FRP, is used for many applications including the largest market which is the boat industry.

The leading manufacturers of gelcoat polyester resins for the bath market are Ashland Chemical, Cook Composites, and Valspar.