Personalized Babys 1st St Patricks Day Irish Shamrock T-Shirt. lots of shamrocks with buffalo plaid Irish hat and babys 1st St Patricks Day message 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.