Personalized 100 Days Smarter | 100 Days Of School T-Shirt. Our 100 Days Smarter design features vibrant colors and a playful illustration that will bring a smile to anyone's face. Made from high-quality materials, our apparel is comfortable and durable, ensuring that your child can enjoy wearing it for many more days to come. 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.