This hard-bound sketchbook features high performance, pH neutral, lignin- and chloride-free paper. The heavy-weight 180 lb. paper has a smooth white surface that is suitable for all dry media and ink. With both internal and surface sizing, it will accept light washes, wet media and watercolor as well. From Stillman & Birn. 100 lb. paper Bright white, smooth, extra heavyweight surface It will accept light washes, wet media and watercolor as well.