Personalized Best Grandpas Have Mustaches Long Sleeve T-Shirt. Long Sleeve T-Shirt - White with old time baseball style text that says THE BEST GRANDPAS HAVE MUSTACHE'S with a big handle bar mustache for the word MUSTACHE. Pre-shrunk 100% cotton 6.1 ounce long sleeve t-shirt. Double-needle stitched neckline and sleeves. Quarter turned. Shoulder-to-shoulder taping. Adult: S, M, L, XL, 2XL, 3XL