20 lb. basis, acid-free, versatile layout bond, printed with a non-reproducible blue grid on one side. Smooth opaque surface, suitable for pencil or ink with good erasing qualities. Laser, copier, and inkjet compatible. Commonly used by draftsmen, architects, and engineers for plotting graphs, drawing diagrams, statistical data, etc. Alvin has been the professional's choice for drafting tools and drawing supplies for over half a century. Since 1950, we have been known for our wide selection of high-quality products at a fair price. Our tools help bridge the gap between ideas and innovations.