Rocket Factory Pi vs. Square Root of Minus One Men's T-shirt We only use the softest, 100% pre-shrunk cotton tees for exceptional comfort and quality. The graphics are printed professionally by hand and carefully inspected each time to ensure a print that will look great for years. All our designs are printed in Montreal, Quebec and are ready to wear immediately upon arrival at your door. We sew an original Rocket Factory tag onto the hem of each of our shirts, so you know you're not being short changed by imitators. This design is men's, however most of our designs are available in women's as well as youth and toddler sizes.