These Strathmore drawing papers are acid-free with medium tooth to the surface. The 400 Series Drawing paper is a little heavier and readily accepts pen & ink, pencil, crayon, charcoal, light washes and markers. Its non-reflective surface and uniform formation make it especially suited to line drawings and technical artwork. The 300 Series Drawing paper was designed with students in mind but is invaluable to any artist who uses dry media.