Mineral Paper is similar to traditional wood pulp-based paper but is made with calcium carbonate from rocks rather than tree pulp and is considered to be an environmentally friendly alternative. This water-resistant paper has a smooth finish, yet enough tooth and absorption for use with a variety of mediums including paint, pencil, pastel, pen and marker. It's strong enough to be embossed and is tear resistant for many uses including delicate die cuts. It is light-weight, yet won't buckle even with the wettest mediums. Each pad contains 20 sheets of bright white, vellum surface, acid-free 100lb. sheets.