Um The Element Of Confusion Funny Vintage 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 Check out all of our Funny Science Shirts. Um The Element Of Confusion Funny Chemistry Periodic Table T-Shirt Our Tees are the perfect gift for someones Birthdays, Family gifts, Christmas presents, or any Special Day. Lightweight, Classic fit, Double-needle sleeve and bottom hem