RTFM T-shirt - Geeky Nerdy Tshirt 90% Cotton 10% Polyester 100% pre-shrunk cotton in all colours (exc grey, Antique Jade Dome, Antique Cherry Red, Antique orange, Antique Sapphire 90% cotton 10% polyester, Heather Navy Dark Heather, Heather Red (50% polyester 50% cotton), Heather Royal, Heather Purple, Heather Orange Heather Maroon (65% Cotton 10% Polyester) Washable up to 40C inside out with similar colours Taped neck & shoulders to give a better fit Tumble dry on low. Not suitable for dry clean Double stitched sleeve & waist hem for durability