Lungs 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 Wear to your next doctor appointment and he or she is sure to get a chuckle out if it Great for science teachers, students or doctors Lightweight, Classic fit, Double-needle sleeve and bottom hem