Personalized Happy 100th Day Of School Women's V-Neck T-Shirt. Happy 100th day of school Women's V-Neck T-Shirt - Heather is a great fun way to celebrate this school year milestone with a class party. 5.0 oz., 100% pre-shrunk cotton Athletic Heather is 90/10 cotton/polyester 1x1 rib collar with mitered v-neck Shoulder-to-shoulder taping Ladies' fit