Fly Line Density & Color

Well, we are almost done in our exploration of fly lines. Just a few more things to go over. On this page will cover the exciting topics of Fly Line Density, Fly Line Color and How to Decipher a Fly Line Box.

Understanding Fly Line Density

Fly line density is a very simple term to grasp, actually. All fly line density means is whether the fly line float, sinks, or just partially sinks. Simple.

A floating fly line is by far the most popular and versatile fly line. A floating fly line, as the name suggests, floats completely. It does not sink unless the line is weighed down. If an angler can own only one fly line, make triply sure that it is a floating one. Through the addition of weights an angler can always make a floating line a "sink-tip" line.

By contrast, a sinking fly line sinks - completely. How fast it sinks (known as it sink rate) is variable - depending on the sink rate of the line. Some lines sink very fast, others very slow. The point, though, is the the entire fly line will sink - and will sink at a uniform rate. As a sidenote, the "sink rate" of a fly line will be noted somewhere on the fly box, measured in "fps" - feet per second.

Sinking fly lines are great for big water fishing, particularly lakes and saltwater. They have limited utility in an average river and are rarely used here in Montana.

Since sinking fly lines have limited utility for trout fishing, but because floating fly lines don't always do the job of pulling down nymphs into the depths of the river quick enough, a hybrid was designed - the "Sink-Tip" fly line.

On a sink-tip fly line, only the first 10 to 30 feet of the fly line sinks. The remainder of the line floats. The purpose of this line is to allow for fishing of nymphs and streamers in the depths of rivers where the current is moderately fast. The heavy line, especially if used with some additional weights, can bring a nymph down to depth quickly and keep it there.

For trout fishing, the angler will want to first get a floating fly line. Later, money and desire found, a sink-tip fly line can also be purchased for those "special situations" where the line really is needed.

Understanding Fly Line Color

Let's get this out of the way right now. During daylight hours, especially on bright days, it is impossible for a fly line to just "blend in" and remain hidden from the trout. When seen from the bottom of a river where the fish live, all fly line looks the same when they look upward - a long, black line snaking across the top of the water. From the bottom of the river, the color of a fly line is immaterial. From a trout's perspective, the fly line is a solid, unnatural thing that is lying on top of the water.

Because of this, the color of a fly line for general daylight use does not matter. The fish will see them all. As such, when selecting a fly line color - get a color that you can see easily. Take your choice, green, yellow, orange, red, pink - whatever. Pick the line that you can most easily see in the type of fishing conditions you find yourself in.

Now, during very low light conditions - particularly if you fly fish at night for bass and such - fly line color can indeed be important. Oddly, pure black isn't the best color. Few things in life are ever "pure black." Instead, the consensus is for various shades of dark brown/dark gray - depending largely on the color and clarity of the water where you'll be fishing.

Understanding Fly Line Codes

A person new to fly fishing can be forgiven for not understanding a word on a fly box. To new anglers, the codes used on the fly box make absolutely no sense what-so-ever. Yet, once you understand how they work, the codes on fly boxes are a life-saver. Here's some examples.

  • WF-5-F : This code means that the fly line is a weight-forward taper fly line, with a weight of 5, and floats.
  • DT-6-F : This code means that the fly line is a double taper fly line, with a weight of 6, and floats.
  • WF-7-S : This code means that the fly line is a weight-forward taper fly line, with a weight of 7, and is a sinking line. How fast the line sinks (it's sink rate) will be listed on the box.
  • DT-3-F/S - This code means that the fly line is a double taper fly line, with a weight of 3, and is a sink-tip fly line. The sink rate of the fly line, as well as how much of the line actually sinks, will be listed on the box.
  • L-6-I : This code means that the fly line is a level taper fly line, with a weight of 6, and is an intermediate sinking line. The sink rate of the fly line will be listed on the box.
  • ST-5-F : This code means that the fly line is a shooting taper fly line, with a weight of 5, and floats.

Just remember, on fly line boxes, the taper of the fly line is the first code (DT, WF, L, ST), the weight of the fly line is the second code (1-14), and the density of the fly line (S, F, F/S) is the third code.

Shop & Compare Fly Lines

There's a multitude of places to buy quality fly lines. Below are some suggested online retailers.

  • Fly Lines at Amazon - Amazon carries a wide selection of fly lines, including those from Orvis, Scientific Anglers, Air Flo, Cortland, Rio and others.
  • Cabela's - Carries their own brand of fly line (which is good quality), along with many other leading brands.
  • Orvis Fly Lines - Amazon sells the full selection of Orvis fly lines.
  • Sierra Trading Post - Carries lots of overstock and discontinued fly lines (and other fly fishing gear). A fine place to shop for gear that is "on sale."