Orvis Gel Spun Fly Line Backing, 35 lb Test, White- 100, 200, 300, up to 1200 yds Braided from gel-spun polyethylene, this incredible fly line backing is 10 times stronger than steel in equal diameters. Use this high capacity fly line backing for big game angling. Maximum strength fly line backing with up to 60% more capacity than Dacron. Orvis fly line backing is as trustworthy as our passion for the sport. Made in USA. Various lengths available wound from bulk spools of OrvisGel Spun Backing. You only have to buy what you need - enough to fill one reel or buy in bulk.