Strathmore 400 Series Gray Scale paper is a woven textured heavyweight (80lb or 216 gsm) paper in gray scale colors ranging from white to black. There are three sheets each of white, black, and three intermediate greys in the pads. It is great for value studies using charcoal, pastel, chalk and sketching sticks. Strathmore 400 Series Gray Scale paper is an acid free paper, making it ideal for finished artworks. The paper is suitable for graphite pencil, colored pencil, charcoal, sketching stick, soft pastel, mixed media and oil pastel. Glue Bound Pads have flip-over covers.