Personalized Happy 100 Days Of School T-Shirt. Get ready to capture those unforgettable moments with our 100 days of school design apparel and make this milestone even more special for your child! 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.