These hard-bound art books contain the same high-quality paper used in Strathmore fine art pads. Their lightly-textured matte covers are a dark chocolate brown and the durable Smyth-sewn binding allows pages to lay flat. The 500 Series Mixed Media Art Books feature 90 lb. (190 gsm) 100% cotton fiber, acid- and lignin-free archival paper that is excellent for watercolor, gouache, acrylic, graphite, pen and ink, colored pencil, marker, pastel and collage. The paper is internally sized for wet media with a durable vellum finish for drawing techniques.