I Periodically Wear This Shirt Periodic Table Science Tshirt 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 This shirt features the periodic table with the statement "I wear this shirt periodically". Fun pun tshirt! Makes a great gift for the teachers, professors and college students! Lightweight, Classic fit, Double-needle sleeve and bottom hem