It's a leaf fibre, composed of long slim cells that form part of the leaf's supporting structure. Lignin content is a high 15%. Abaca is prized for its great mechanical strength, buoyancy, resistance to saltwater damage, and long fibre length – up to 3 m. The best grades of abaca are fine, lustrous, light beige in colour and very strong. Once a favoured source of rope for ship's rigging, abaca shows promise as an energy-saving replacement for glass fibres in automobiles.