Studio Calico Elementary School Collection - 12 in. x 12 in. Harpers Rule Cardstock. This is a double sided 12 in. x 12 in. heavy weight cardstock paper full of different vintage rulers and elementary school writing tablet design on the other side. This collection coordinates so well together. This is the paper used in the September 2010 "Elementary School" ATC kit. Great paper for school ATCs and other teacher and school related projects and scrapbooks.