Personalized Cowboy 1st Birthday Western T-Shirt. Whether you're looking for a gift for a one-year-old or planning a Western-themed birthday party, our Cowboy 1st Birthday collection has everything you need. 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.