Rio Fly Line Backing - Dacron - Chartreuse - 20LBA high quality, super smooth braid that is 100% reliable. RIO's traditional Dacron braided backing features high strength and low stretch and is unsurpassed in quality. A good compromise between thinness and the ability to make blind splice loops. It's easier to knot than other brands that are very thin but have too tight a weave for a blind splice loop.