There are 3 options for the short sleeve T-shirts: 1) Basic 50/50 cotton/poly T-shirts in size youth small to adult 5X (29B/29M). 2) Softer, 4.3 oz, 90/10 combed ring spun cotton/poly-heathered grey or 60/40 combed ring spun cotton/poly-white in sizes youth XS - adult 4X (DM130y/DM130/DM108). 3: 3.8 oz, 100% polyester interlock with PosiCharge technology (moisture wicking/drifit style) in size youth XS to adult 4XL (YST350/ST350).