Personalized 13th Anniversary Butterfly T-Shirt. 13th Anniversary T-Shirt - Black has a pink butterfly with thirteenth anniversary quote to celebrate your wedding anniversary special occasion Wardrobe essential for looking good, 24/7. 5.0 oz., pre-shrunk 100% cotton. Seamless 1x1 rib collar. Shoulder-to-shoulder taping. Double-needle stitched sleeves, bottom hem and front neck. Note: greys are a cotton/polyester blend.