Personalized Train 1st birthday It's My First Birthday Baby's First T-Shirt. Make your birthday boy or girl feel extra special with this fun and festive design. It's a wonderful way to commemorate their first year of life, filled with laughter, love, and cherished memories. Get ready to create lasting moments as you celebrate this incredible milestone! 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.