Wood wool

Wood wool, known in North America as excelsior, is a packaging and industrial material made of thin wood slivers shredded from logs of softwoods such as poplar, aspen, pine, spruce or eucalyptus using specialized shredding machinery, producing strands typically one and a half to twenty millimeters wide and around five hundred millimeters long that can be compressed for transport and later expand back toward their original volume; the fibers are sometimes washed to remove dust or kiln dried to reduce moisture. Commercially it is used as packaging cushioning, as the cooling pad material in evaporative swamp coolers, in erosion control mats, and as the base material for cement bonded wood wool boards, and it has historically also served as upholstery and toy stuffing, with continuing use today as animal bedding, garden mulch, a hydroponic growing medium and archery backstops.