This Arches Watercolor Block contains 20 sheets of 140 lb. (300 gsm) , acid free watercolor paper. Hot press watercolor paper is ideal for watercolorists who want a smooth surface with even washes. This paper is also deal for drawing as well as pen and ink washes. Arches has a tradition of creating high-quality papers for over five centuries. This watercolor paper is superior quality, mold-made paper from the Arjomari Mills of France. This convenient block is glued on all four sides, keeping your surface taut and allowing you to create artwork instantly.