Top-bound notebook features carbonless, 15 lb. paper that has a white original sheet and blue copy sheet for a convenient way to keep copies of your work. 50 sets of graph-ruled paper are consecutively numbered for quick reference. Removable backer can be easily positioned under the blue sheet to prevent bleed-through. Front cover is made from durable, 20 point material to protect the interior pages from damage. Notebook is perfect for labs, science classes and more.