Paper and writing supplies include a broad range of writing implements, paper and accessories. Pens, pencils and markers are available for note taking and sketching. Ballpoint pens are a cost-effective tool for permanent markings. Many mechanical pencils feature a refillable chamber for optimal efficiency. Writing paper in different sizes, rulings and colors helps facilitate optimal organization. Notebooks with perforated paper are ideal for tearing out individual pages. Composition and memo books may have a center-sewn, tape-bound design for maximum durability. Clipboards hold loose sheets of paper and provide a flat, sturdy writing surface.