Make room in your t-shirt drawer, because today we’ve added three new shirts to the mental_floss store: “I’d Give My Right Arm To Be Ambidextrous,” “Thomas Aquinas: The Original Deep Fat Friar” and “The Comma Sutra: Making Grammar Sexy since 1875.”

To celebrate their arrival, all our shirts are currently 15% off. Just enter the coupon code “moretees” before checkout. (Discount doesn’t apply to package deals or Outlet Store items.) If you’re pondering a shirt purchase, consider adding a subscription to mental_floss magazine, which is like a witty t-shirt, only rectangular and with more pages.