We carry these sketch books after a request from one of our local art teachers. The 25% cotton content helps the pages stand up to washes of ink or watercolor. The Natural White color softens the page and lends it self to nature sketches. The 50 sheets of 130 lb paper are spiral bound to help keep everything together as you take it with you when you go sketching. It also has a nice sturdy cover to protect your work as the sketch book goes in and out of bags.