Personalized 1st Birthday Polka Dots Cupcake T-Shirt. Our 1st birthday outfit for boys is designed with comfort and style in mind. Crafted with soft fabrics and cute details, this outfit is ideal for your little man's first birthday celebration. Whether he's crawling around or posing for pictures, he'll look absolutely charming in this outfit. 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.