Orvis Gel-Spun Fly Reel Backing is ideal backing for big game angling. Orvis Gel-Spun Fly Reel backing offers maximum breaking strength with up to 60% more capacity than Orvis Braided Dacron Backing. 35-lb. test Gel-Spun Backing gives you more capacity than using 20-lb. Dacron. Braided from gel-spun polyethylene, this incredible fly line backing is 10 times stronger than steel in equal diameters. A very small diameter for higher yardage on the reel means slower spool rpms on runs and faster pickups. Gel-Spun has virtually no stretch, is extremely abrasion-resistant, yet it has a very low coefficient of friction so it will not damage the guides on your fly rods. It also retains 100% of its strength while in the water. Unaffected by UV, gas, oil, salt or detergents. Gel Spun fly line backing comes in 35- and 50-lb. test.