Premiere 500 Series is a 100% cotton fiber paper smooth and is the finest and unsurpassed in quality paper in the comic book art board industry. The smooth surface offers the artist precise and clean lines and a chance for detailed ink work and suited for pencil and marker. The 3-ply thickness gives the paper extra durability. The main advantage of Strathmore is its 100% acid free feature. This prevents the signs of aging such as yellowing.