These hard-cover sketch books feature high performance, pH neutral, lignin- and chloride-free paper that is milled from pulp with an alpha cellulose content that exceeds 87%. The heavy-weight 100 lb. paper has a toothy, ivory vellum surface with superb erasure characteristics and is suitable for all 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 super tough and resistant to warpage. The hard-bound books contain 62 sheets and the wire-bound books have 50 sheets. Bound in the USA.