Personalized This Kid is 3 Birthday Toddler T-Shirt. This kid is three! Celebrate your child's third b-day with this cute thumbs up 3 design. Happy Birthday 3-year-old! A toddler-soft cotton tee in look-at-me, big kid colors. 4.5 oz., 100% combed ringspun cotton. White is sewn with 100% cotton thread. Topstitched rib crew neck. Double-needle stitched sleeves and bottom hem. Shoulder-to-shoulder taping.