CORTLAND GEL SPUN FLY LINE BACKING 50LB YELLOWCortland Gel Spun Fly Line Backing Yellow (50lb) The Cortland Gel Spun Fly Line Backing is designed for anglers who need maximum strength and reel capacity in demanding fishing situations. Constructed from super high strength gel spun fibers, it is thinner and stronger than traditional Dacron, enabling you to spool more backing onto smaller reels without compromising reliability. With a tight, round braid, this backing lays flat and smooth on the