Personalized World's Greatest Dad Blue Text Youth T-Shirt. World's greatest dad in blue text with the earth in place of the letter O in the word world is a unique gift design for dads and stepdads on birthday, holidays and Father's Day. 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.