Personalized Happy 100 Days Of School T-Shirt. Celebrate your child's milestone with our adorable "100 Days of School" design apparel! This cute and happy design is perfect for commemorating their first 100 days of school 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.