Personalized 100 Days of Genius 100 Days Of School T-Shirt. Whether you're attending a school celebration or organizing a themed event, our outfit will surely make you look stylish and in tune with the festive spirit of the 100th day of school. Additionally, it can serve as a matching outfit for daughters, offering a delightful way to celebrate together. Wardrobe essential for looking good, 24/7. 5.0 oz., pre-shrunk 100% cotton. Seamless 1x1 rib collar. Shoulder-to-shoulder taping. Double-needle stitched sleeves, bottom hem and front neck. Note: greys are a cotton/polyester blend.