Personalized Mommy Runs Half Marathon T-Shirt. Cute my Mommy runs 13.1 T-Shirt - Black half marathon race themed outfit for daughter or son 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.