BINDER SKETCHBOOKS BY KUNST and PAPIER: Gray binder board covers with linen spines. The sewn and gauze-spliced bindings provide strength and durability. This unique binding method allows the books to open flat and beyond without damage to the binding. Linen spines available in five assorted colors. The heavyweight acid-free paper is an excellent support for all dry media and is suitable for water-based markers and light washes. It is also pH buffered lignin and chlorine-free.