Fly Line Backing Types

Fly line backing is used to provide volume to a fly reel so the fly line can be unspooled or retrieved with fewer revolutions of the spool. Since a fly line is only 90 feet long, backing also acts as protection against a fish making a run and taking all the fly line with it.

  1. Dacron Backing

    • Dacron backing is made of a polyester material and is the type most often used by fly fishermen. It is the one most often recommended by reel manufacturers because of its durability and resistance to cutting into itself when tightly wound on a spool. Braided backing comes in either 20-lb. or 30-lb. test.

    High-Modulus Polyethylene Backing

    • High-modulus polyethylene backing, also known as gel spun, is newer and not as common as Dacron backing. Its main advantage over Dacron is that it has a higher strength per diameter. The smaller diameter means that more footage of a specific weight will fit onto a spool in similar volume to Dacron.

    Monofilament Line

    • Monofilament line can be used for backing, but it is not recommended. It may be cheaper than Dacron or polyethylene backing, but it can coil and cut into itself when tightly spooled. It also has memory, meaning it is not limp as other material and will coil back into itself like a spring if unspooled. If you can be sure of not letting out all your fly line and getting into your backing, then using monofilament is fine.

    Old Fly Line

    • If really looking to economize, you can re-use an old fly line for backing. It has a greater diameter than the other backings, but because it is only 90 feet long, it may not be sufficient to fill the spool of a large capacity reel.