Profile: Stern & Co., I specializes in plastic resins, sheet, roll stock and color concentrates. Our product line includes plastic resin, plastic sheet, and color concentrates. Our polystyrene N2380 is a high heat crystal polystyrene. It is featured with high molecular weight with optical activities. It is used in foamed trays and thick walled injection moldings. Our color concentrates are available as pellets in both standard and custom-matched colors.