5 oz./yd (US) 8.1 oz./L yd (CA) 100% preshrunk cotton, 23 singles. Athletic Grey is 90/10 cotton/polyester (US only). Sport Grey is 90/10 cotton/polyester (CA only). Heather and Safety colors are 50/50 cotton/polyester. Cover seamed neckline. Taped shoulder to shoulder. Double-needle topstitched collar, cuffs and hem. USMCA Certified.