Personalized It's My Birthday Long Sleeve T-Shirt. It's My Birthday! A cute little cupcake is dancing with joy because it's your birthday! Cute birthday gift for that special someone! 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