Personalized Happy 100 Days Of School T-Shirt. Our 100 Days of School design apparel features a delightful and eye-catching design that showcases the excitement of reaching this special milestone. With vibrant colors and playful graphics, it's a fun way for kids to express their love for learning. 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.