Personalized 1st Day of Preschool Girls Mermaid Tail T-Shirt. 1st day of school apparel T-Shirt - Navy Blue with preschool girl mermaid tail design 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.