"Technically The Glass Is Always Full" 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 Great funny and uplifting scientific, optimistic positive message with math-physics spin! Look and feel good in this crew short sleeve men's and women's comfortable tee shirt Lightweight, Classic fit, Double-needle sleeve and bottom hem