Personalized Irish Grandpa Shamrock Long Sleeve T-Shirt. Irish Grandpa Long Sleeve T-Shirt - Charcoal for St Patrick's Day has a border of green Irish shamrock clovers. 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