These hard-cover sketch books feature high performance, pH neutral, lignin- and chloride-free paper. The heavy-weight 150 gsm paper has a smooth white surface, and is suitable for pen, ink and dry media. With both internal and surface sizing, it will accept light washes as well. The covers are made with extra heavy-weight binders' board that is tough and resistant to warpage. The hard-bound books contain 62 sheets and the wire-bound books contain 50 sheets. Bound in the USA.