9oz ( 300 gm ) 80% cotton 20% polyester blend ring spun cotton 100% cotton 30 single face yarn split stitch double needle sewing on all seams twill neck tape 1 x1 ribbing at cuffs and waistband standard fit. There are a 3 end knit with 100% cotton face yarn, 100% Polyester middle yarn and 80% cotton 20% poly back yarn . We chose this blend to achieve some stretch and ultra-soft feel.