Personalized World's Best Great Grandpa Long Sleeve T-Shirt. Great Grandpa Long Sleeve T-Shirt - Charcoal gift has World's Best Great Grandpa logo on a Father's Day gift for him. 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