Personalized My first St Patrick's Day Baby's First St Patrick's T-Shirt. Dress your baby in this delightful outfit and let them join in the fun of St. Patrick's Day celebrations. It's a wonderful way to introduce your child to the joy of traditions while keeping them stylish and cozy. 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.