Keep Calm I'm A Rocket Scientist Funny T-Shirt 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 Quality T-Shirt Printed & Shipped by Amazon Large Bold 15" Wide Print. Lightweight, Classic fit, Double-needle sleeve and bottom hem