Made of low stretch Dacron, it won't damage your reel when wound in under the pressure of a big fish. Available in 20# test for most applications.
Scientific Anglers Backing Dacron Fly Line, 20 lb/250 yd, Yellow
Rio Fly Line Backing Dacron, 200yd Fly Fishing Backing
Scientific Anglers Dacron Backing - Specialty Colors - The Fly
SA Fly Line Backing, Dacron, 20 lb Test, White- 100, 150, 200, 250, 300, 400, 600 up to 5000 yds (1500 yds) (100 yds) (100 yds) : Sports
SA Fly Line Backing, DACRON, 20 lb Test, WHITE- 100, 150, 200, 250, 300, 400, 600 up to 5000 yd
Scientific Anglers Specialty Tri-Colored Dacron Fly Line Backing
Fly Line Backing in the 30lb strength and the color is black from our friends at Scientific Anglers. Standard Dacron Backing is built with advanced 3M
Fly Line Backing - 30 lb
Timco SA Backing Line 250YD 20LB (Fly Line Backing Line) (Timco Fly Line Backing Line)
Scientific Anglers フライライン 250ヤード ダクロンバッキング
Scientific Anglers Dacron Fly Line Backing - Hunter Banks Fly Fishing
, 20# 250 yd
Scientific Anglers Dacron Fly line Backing, White
Dacron Backing Scientific Anglers
Scientific Anglers Dacron Backing in Blue 20lb - 200yds