Scientific Anglers' Standard Dacron Fly Line Backing is extremely thin and highly abrasion-resistant, which means that you can store plenty of it on your reel and rely on it when the time comes. It runs though both your reel and rod virtually friction-free, so that monster bonefish won't get a chance to break off. When you are fighting the fish of a lifetime, your backing should be the last thing on your mind. Choose Scientific Anglers' Standard Dacron Fly Line Backing and fish with confidence. High abrasion resistance Colorfast High visibility.