ThisWear Pi Day 2016 3.1416 Round It Up Math Graph Stem Premium Hoodie Sweatshirt 10% cotton Celebrate Pi Day in style with this funny Pi design. A perfect birthday gift or gag gift for a mathematician. 90%/10% cotton/poly, (Light Steel and Ash are 85%/15% cotton/poly), with low pill, high stitch density fabric. The design is printed with new age printing technology, direct-to-garment. It is printed with a water-soluble and eco-friendly ink. It is cured with a heat treatment process to ensure the color-fastness and lasting durability of the design. Authentic ThisWear  design printed with pride in the United States. This is not an unauthorized replica/counterfeit item. This is an original inspired design and does not infringe on any rights holders rights. Words used in the title/search terms are not intended to imply they are licensed by any rights holders.