Pi Day T-Shirt You Want A Piece of Me Solid colors: 100% Cotton; Heather Grey: 90% Cotton, 10% Polyester; All Other Heathers: 50% Cotton, 50% Polyester Imported Machine wash cold with like colors, dry low heat Funny Math Humor with angry eyes PI symbol Great for PI Day, math competitions, mathletics, teachers, quiz bowl, nerds, geeks Lightweight, Classic fit, Double-needle sleeve and bottom hem