Fly-line 101

Fishing itself can be a very simple activity. You can cut a piece of bamboo, get a six-or-eight foot piece of fishing line, tie on a hook, dig up a worm, or even mix a little flour and water together to form a little ball and attach the bait to the hook. Drop it in the water and you would be surprised at the likelihood that a small fish will grab the bait, and you will be on your way to a lifetime of fun.

FlylineIn the world of sportfishing, tackle comes with specialized terms. Fly-fishing – arguably the most challenging sub-category, has unusual codes designed to confuse the rest of us.

From its humble beginnings, fishing has become one of the most popular pastimes in the world, with people fishing in Japan nearly as much as they watch baseball. Fly-fishing – specifically with the kind of line you use to catch fish with a fly-rod – is a sport gone to its most complex and challenging heights. And we are here to tell you about fly-line: How it is formed, how it -- and not the lure -- is the thing you’re casting to the hungry fish, and why it is so very addictive. In this article, we break down these innocuous looking loops of plastic into something comprehensible.

Understanding How Fly-line Works

Most fly-line is designed to float on the surface. Often, it is designed so that just the very tip can sink a little or be suspended in the water columns. They can float their entire length, sink their entire length, or sink only around the tip where the fly-line is connected to the leader material. 

fly line on reelAll fly anglers use leaders because the diameter of the fly-line and the high visibility in the water makes is unlikely to work if you simply tie a fly to what is basically a rope in the water.

The fly-line that you select will be based on the types of fish you are normally going to target with this specialized and challenging equipment. All fly-lines have the same basic structure. There is a nylon core that is wrapped in a sheath of plastic material. It does not soak and absorb water unless there is something wrong with it. It is available in a variety of sinking speeds, from slow to fast. Lastly, sinking line refers to the entire line sinking, and is available at a slow-to-fast sink rate. The diameter of the length of line is also variable and will alter performance and handling characteristics. Fly-lines range in length from 75 to over 120 feet.

Types of Lines for Fly-Fishing

In the world of sportfishing, tackle comes with specialized terms. Fly-fishing, which is arguably the most challenging and toughest-to-master subcategory of the sport. Let’s try to make it easy to understand by looking at the kinds of fly-lines there are.

flyfishing-illustration-types-flyline-optThis simple illustration shows you the primary types of fishing line. Although we talk about more than three, there are three basic forms – level; thicker in the middle than on the ends; and thicker on one end – the one you cast.

  • Front Taper: Tip of the line (the end that will be closest to the fishing hook)
  • Belly: Middle of the line
  • Rear Taper: End of line (the end closest to the arbor of the reel)

Here are terms that pertain to performance characteristics of fly-line:


Weight Forward Lines
A very good casting fly-line. Used by bass fisherman and saltwater anglers who throw big flies in windy conditions. Can be floating, slow sinking, fast sinking and very fast sinking.
Shooting Taper
The forward part of weight forward line without the backward taper and the level rear sections. The line has a shorter forward taper with weight concentrated in the forward casting portion. Furthest casting of any fly-line and therefore good for distance casting. Also called shooting head or rocket taper.
Bug Taper
Weight forward lines where the front taper is shorter and heavier. Good for casting very bulky light flies, bugs and poppers
Double Taper
For the most delicate placement of the fly, with very little splash. Will not spook or scare the fish. Quiet. Double taper floating lines are great for dry flies. Historically this kind of line was used by anglers fishing for trout in small streams or midsize rivers, where casting distance is not nearly as important as the touch and feel of the line. You do not need 80’ casts if the stream you are fishing is 100 feet wide. Normally you’re in the water with those fish and your casting needs be done under heavy bush, on fast running water and in just the perfect spot. Lures do not stay where they need to be to catch a fish for more than a few seconds at most. Repeating casts to place a tiny gnat fly in a smooth pool behind a boulder in the stream does not need you to double-haul. Line with a double taper lets you use one side for a few seasons, and when all is worn and scratched simply turn it around on the reel and get fishing for another few years.
Level Line
The first fly line was braided from vegetable fibers in all likelihood, and the taper (or lack thereof) was hardly an issue. Flies were “dappled” – dropped onto the surface of the water from a twelve or fourteen food branch or bamboo rod. No casting was necessary. It was only in the twenties and thirties that manufacturing technologies allowed tapered lines to be made in the first place. Level wind is old-fashioned, hard to cast, and fairly useless in today’s high-technology and finely-shaped flylines.
Variweight Taper Lines
A double taper line where the two tapered sections are of unequal weight. Versatile, one Variweight taper line can be used on different weight rods. Intermediate Lines: A floating line with 10 feet of sinking tip. This makes it easier to pick up line to cast (as opposed to casting a sinking line or a floating line). Another type of intermediate line is made to float when it is dressed with a float-ant ?? What is this? PK preparation or to sink slowly when used without such dressing.
Running Line
Long, thin part of any fly-line that connects to the backing or it can be attached to the back of a shooting taper line allowing the angler to quickly change the type of fly-line being used by interchanging only the head section.
American Fishing Tackle Manufacturers (A. F. T. M. A.) decided fly-lines should be identified by weights of their forward sections ranging from size 1 being the lightest to size 15 for the heaviest. These designations apply regardless of whether the line is level, double taper, forward taper or anything else. This information will be included on the fly rod blank.
Wetting Agents
Products that aid to sink the fly line.

Buying Fly-line and Understanding What You Are Buying

Look at the rows of flyline available at a local tackle store and the terminology really kicks in. What is a DT/8? What if you are going tarpon fishing and are willing to spend a thousand dollars to gather the best stuff money can buy? Do you have any idea what all the little letters mean? We do. Below, the main kinds of line are listed with their characteristics.

  • L - level (same diameter from and to and)
  • DT - double taper
  • WF - weight forward
  • ST - single taper (shooting taper)
  • F – floating
  • S – sinking
  • F/S - wet tip (floating line with sinking)
  • BBT - Bass bug Taper
  • FS - fast sink
  • EFS - extra fast sink
  • SWT - saltwater taper

This line from Scientific Angler is a Torpedo 12 weight. The image is from Amazon.com – a great place to search for and purchase fishing tackle. As easy as it is to use an online site like this, it’s still a good idea to meet fellow fly-anglers to learn from somebody with experience. Our Fly-fishing Forums are a great place to start.
Buy on Amazon

Which Fly-Line Should I Use?

Fly-line, fly-rods, and fly-reels are matched according to their stated “Weights.” For example, an 8-weight fly-rod – something you will often find in the hands of experienced saltwater anglers – is a combination of an 8-weight rod and reel, and 8-weight line. Increasingly, the most common lines are weight-forward or torpedo lines (there are lots of names, but that means the most weight and diameter is in the front of the line closest to the leader connection). You will replace leader, and depending on the pressure you put it through, you will replace fly-line. You could very well purchase a combination to start with, but the leader and the line are consumables to some degree, with leaders coming frayed and requiring replacement multiple times on one trip.

There is a lot to learn about fly-fishing, so we are sure there are other things available in related stories you will find at the end of this one. Suffice it to say it’s important that you match rod, reel, line, and leader together when you’re designing or replacing components of a fly-fishing rig.

Important Flyline Terms: Backing, Leaders & Tippet

Backing, usually made of Dacron or gel-spun (braided line) material, is added from the arbor of the fly-reel to the rear taper of the fly-line. Braid has a much thinner diameter and is used when the angler wishes to have a large amount of backing such as when fly-fishing for for big game species that will likely pull a lot of line. It provides an extra length of insurance to anglers as they may go up against some hard fighting fish that will run out all available fly line on the reel.  Fly-line backing should  range  in length from 150  to about 200 yards in length, which can go by pretty fast when catching some of the sportier fish in the sea. Twenty or thirty pound test is commonly used.

The length of your leader depends on the water conditions. Shorter leaders are easier to cast but more likely to spook fish. Use the longest leader you can comfortably cast. The tippet is a length of fine diameter nylon that is tied to the leader, and will be tied directly to the fly. This should lie out smoothly, and ensure the most natural presentation of the fly.

This sequence may seem confusing to the new fly angler. The leaders are sized in decreasing diameter from the front taper of the fly-line to the fly itself. The correct sequence will be fly-line, leader, tippet and lastly, the fly. Saltwater leaders range from approx 6 feet to about 15 feet. The species you are after, the conditions you are fishing in, and the fly you are throwing will determine the length and strength of your leader.

Many anglers choose to make their own leaders, but it's much easier to buy ready-made leaders. When making a leader, it must be of sufficient diameter and stiffness to cast properly. A butt that is too thin forms a V when bent with your fingers. A butt of the correct size will form a U.

fly line leader scientific angler
You can purchase leaders that are already tapered, and quite frankly they are perfectly fine and will catch just as many fish as a leader you spend an hour tying yourself. This one is from the same company we use for a lot of our fly-line and leaders – Scientific Angler.

Tapered leaders are made to roll the fly out as a continuation of the line and to make the leader fall to the water in a straight line rather than in a coil. If the butt end of the leader is the wrong diameter for the end of the fly-line, the line end and leader butt will act as a hinge and thus land improperly instead of the leader acting as a continuation of the line. If the tip end of the leader is too stiff for the size of fly, the fly won't land and swim or float in a lifelike manner. If the tip is too light for the size of the fly, the fly may break off in the cast or a fish may break it off.

The right leader is critical! Knowing how to select the proper leader often separates successful from unsuccessful anglers. Tapered leaders are fine, but consider using tippets to increase strength for those big fish or rough structural conditions.

The leader is responsible for the presentation of the fly and is the most vulnerable to abrasion and breakage. Choosing the correct leader and tippet section allows the angler to make an enticing presentation and decrease concern about breaking off.

Final Words About Fly-Line

Fly-fishing anglers have much to consider when setting up their perfect fishing combo. A variety of lines carefully tailor the fishing experience for optimal results. Fly-fishing really teaches the angler to be resourceful and aware of the natural environment. Each component must be carefully considered and matched to the water in which it’s used.

Something to consider about fly tackle is keeping it clean and maintaining it. It’s important to keep good care of any of your line, but quite frankly fly-line is particularly prone to coming apart and decaying if you do not take special care of it. This article about taking care of fly-line will come in handy if you are addicted to the sport of long rods like a lot of our readers are.

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