Personalized My 1st 4th of July rainbow T-Shirt. fourth of July holiday rainbow in red, white and blue for celebrating babys 1st July 4th get together 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.