4.2 oz./yd, 52/48 combed ring-spun USA premium cotton/polyester, 36 singles. Heather Black and Heather Grey are 90/10 combed ring-spun USA premium cotton/polyester. Retail fit. Heat-set fabric. Ribbed crewneck collar. Self-fabric back neck tape and shoulders. Side seams. Double-needle sleeves and bottom hem. Tear away label. USMCA Certified. This product meets the following Sustainable Style subcategories - Sustainable Manufacturing - This brand is working towards an OEKO-TEX Standard 100 certification Socially Conscious Manufacturing - This product was made in a facility that holds a SMETA audit certification.