Spiral bound: The reinforced black iron spiral bound is beautiful and practical,paper can be flipped 360 degrees,flexible and easy to use Premium paper: The sketch book offers 100 sheets of white,lightweight,neutral PH,acid-free paper,which will give your a better sketching experience on account of its slightly textured surface Sturdy back cover: The sturdy back cover of the sketch book is thick enough to provide a great supportive surface to write on,practical and convenient