Strathmore 500 series Mixed Media features professional quality paper that is internally sized for wet media with a durable vellum finish for drawing techniques. Excellent for watercolor, gouache, acrylic, graphite, pen & ink, colored pencil, marker, pastel and collage. 100% cotton fiber, acid free, lignin free, archival, 90lb paper. Durable Smyth-sewn binding allows pages to lay flatter inside the lightly textured, matte dark chocolate brown cover.