Personalized Sweet 16 Stamp Long Sleeve T-Shirt. Sweet 16th birthday Long Sleeve T-Shirt - Pink with a distressed canceled postage stamp, fun pink birthday cake and the number 16. 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