Strathmore 400 Series drawing paper pads contain acid-free, heavy weight, durable, medium surface 80 lb. drawing paper. Natural white paper is ideal for illustrations and final drawings. Suitable for any dry media, pen, ink, and light washes. Pads contain 24 sheets and are spiral bound across the top (the first measurement listed). Pads 8 in. x 10 in. and larger are micro-perforated for clean and easy sheet removal. Suitable for dry media, pen, ink, and light washes Pads contain 24 sheets Wire bound sheets are microperforated for clean removal size: 12 in. x 18 in.