Personalized Greatest Grandpa Youth T-Shirt. World's Greatest Grandpa Youth T-Shirt - White gift has vintage style logo on a Father's Day or new Grandpa gift for him in blue and tan. 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.