Personalized 100th Day Of School Pencil Youth T-Shirt. 100th Day Of School gifts. Smiling School Pencil Youth T-Shirt - White for the teacher celebrating this school milestone each year. Let the good times roll in a durable T-Shirt that takes kids from school to play in an amazing array of colors. 5.0 oz., pre-shrunk 100% cotton. Seamless 1x1 rib collar.