Pizza Pi Day 2017 Math Stem Nerd Geek 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 Italian Pizza Pi 3.14 Math Humor Nerd Geek Gift Think geek math STEM student T-shirts Lightweight, Classic fit, Double-needle sleeve and bottom hem