Personalized Baseball 8th Birthday Youth T-Shirt. Baseball 8th birthday boy. Baseball league style with bats and varsity letters. Sports theme for your 8-year-old's b-day party. Happy Birthday eight-year-old! Let the good times roll in a durable T-Shirt that takes kids from school to play in an amazing array of colors. 5.0 oz., pre-shrunk 100% cotton. Seamless 1x1 rib collar.