Stemmy Shirts: Engineer, Solve Problems Graphic 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 Perfect gift for all engineers and aspiring engineers T-Shirt features various engineering motifs (gears, circuits, and atoms) Lightweight, Classic fit, Double-needle sleeve and bottom hem