Never Trust An Atom They Make Up Everything Science 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 This hilarious science t-shirt will give the lab a good laugh Great gift for scientists, professors, lab rats Lightweight, Classic fit, Double-needle sleeve and bottom hem