Personalized My First St Patty's Day T-Shirt. Dress your little one in this delightful outfit and let them join in the celebration of Irish culture and tradition. Get ready to share smiles and laughter as you celebrate this memorable day 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.