SCIENCE DOESN'T CARE WHAT YOU BELIEVE SHIRT Solid colors: 100% Cotton; Heather Grey: 90% Cotton, 10% Polyester; All Other Heathers: 58% Cotton, 42% Polyester Imported Machine wash cold with like colors, dry low heat Science Equality This premium t-shirt is made of lightweight fine jersey fabric Fit: Slim (consider ordering a larger size for a looser fit)