Personalized Princess 1st Birthday T-Shirt. Pink Princess 1st birthday. This pink heart with a jeweled tiara will make your baby girl's first b-day special. Happy birthday 1-year-old! Everyone loves our Custom T-Shirts! 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.