Personalized Happy 100 Days Of School T-Shirt. Our 100 Days of School outfit is not just for kids. It also doubles as a fabulous costume for women on the 100th day of school. Whether you're a teacher or a parent, you can join in the festivities with our unicorn-themed design. And if you have a daughter, we even offer a matching 100th day of school outfit for girls, so the whole family can celebrate together in style. 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.