Personalized 100 Days Of Genius | 100 Days Of School T-Shirt. The 100 Days Of Genius design features vibrant colors and a playful illustration that will make your little one stand out. It's a great way to commemorate their achievements and show off their unique personality. Whether they're wearing it to school or a special celebration, our apparel is sure to bring smiles and compliments. 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.