Thread Science Math Numbers Tree Calculus Algebra Symbol Equation Formula Pi Men&rsquo;s T-Shirt Printed in the USA. This shirt comes printed on two options: 90% Cotton 10% Polyester or Premium 60/40. The Premium 60/40 option is a super soft Next Level T-shirt made of 60% Cotton and 40% Polyester. If you prefer ultra soft shirts, the premium 60/40 is the best choice. Mens Unisex Adult Sizing, Heather Grey Machine washable: Machine wash warm inside out with like colors. Tumble dry medium. Exclusive Thread Science design. If youre a fun wife looking for great birthday mens apparel ideas for a husband, a parent trying to find the perfect awesome novelty gag graphic t-shirt present for a son or daughter, or a teenager searching for fun cool vintage retro and classic clothes, we offer top quality soft touch tees and merchandise that are sarcastic, witty, old school, interesting, clever and unique. Surprise gifts for everyone; teachers, students, friends, coworkers, and neighbors. Our fashion tshirts use sarcasm and are always hilarious. These shirts make awesome additions to any wardrobe. Our mens and womens designs are great for holidays; Christmas, Fathers Day, Mothers Day, Halloween, Valentines Day, Saint Patricks Day, Thanksgiving, New Years, Easter, Hanukah and the 4th of July. The perfect family idea for a brother or sister, mom or dad, uncle or aunt, or grandma and grandpa. Share our designs, puns and laughs with that special person or people in your life.