Borden & Riley have been supplying a large selection of fine art papers since 1910. #310 Optimum Drawing Sketch is a heavyweight paper with substance. Its smooth finish compliments a variety of rendering styles with any medium such as watercolor, pen, ink, markers, pencil etc. This high quality paper also erases with ease.90 lb. paper, acid-free with superb tooth to create long lasting sketches. Microperforated to allow tearing out pages for display easy.