Fly Fisherman's Tackle Checklist: Fly Lines

Understand how fly line design shapes performance on the water.

January 30, 2026 By Ross Purnell

Affiliate Disclosure: This page contains affiliate links. We earn from qualifying purchases.

Click here to see the full "Tackle Checklist" series.

A great fly line can make a difference in your casting right from the beginning. Here’s how important it is (proportionately): If you have a budget of $200 to buy your first rod, reel, and line, I’d say spend about half on your fly line, and the rest on the rod and reel.

In terms of casting performance, fly lines are even more important than the rod you use. Unfortunately, some fly fishers use lines that are worn out, or lines designed for other purposes. Don’t make these mistakes. Expert fly fishers replace their lines when they lose their buoyancy or slickness. As a beginner, you don’t need the extra challenge of an old fly line that is dry and cracked.

If you are new to fly fishing, and want to get started fishing for trout in rivers and streams, your first fly line should be a general-purpose floating weight-forward freshwater line. Look for a fly line with a lot of weight up front to help you load the rod deeply, even at short distances. Also, get a two-tone line that gives you a visual clue to where the head of the line (the thick part) ends, and the thin running line begins.

A good example is the Scientific Anglers Amplitude Textured Infinity ($130). Expert casters love this line because it’s heavier than the industry standard, and deeply loads even super-stiff, fast-action rods at longer distances. It’s great for beginners for the same reasons: It’ll help you load the rod and feel what’s happening, and the color change from buckskin to bamboo shows you exactly where your optimum loading distance is.

As you progress as a fly fisher, you will need more than just one line. For instance, most floating trout lines are poor choices to cast bass popping bugs, catch trout in deep water, or catch steelhead and salmon in large, swift rivers.

Before you can make a wise purchasing decision for a specialty fly line, it’s helpful to know how the lines are built, and how the core, coating, and taper of each line affect performance.

Core. Think of the core as the skeleton of the fly line. It gives the line its strength, determines how much or how little it stretches, and also determines how flexible it is. Fly lines with monofilament cores generally have less stretch and are less flexible (stiffer) than lines with multifilament cores. Stiff lines cast farther because they “shoot” better and tangle less frequently.

In cold weather and in cold water, however, lines with monofilament cores often have too much memory, leaving you with coils that are difficult to cast. Lines with monofilament cores are not common in fresh water and are best suited for hot weather and tropical species such as bonefish.

Most fly lines have multifilament cores, which give line manufacturers more control over how much memory the line has, how much stretch it has, and how stiff (or limp) it is.

Coating. The coating is the soft, polymer covering the manufacturer applies over the fly line core. Most line companies use polyvinyl chloride (PVC) for the fly line coating—the same PVC used for making everything from credit cards to household pipes. PVC can be made soft and flexible by adding plasticizers, and made slippery by adding lubricants. Fly lines from Scientific Anglers, RIO Products, and Cortland are all made with proprietary blends of PVC.

A line advertised as a bonefish line should have a stiff coating that still shoots through the guides when it is 95 degrees, and won’t turn gummy and more prone to tangling. Conversely, trout lines are specifically designed to perform best in cold water, with a minimum amount of memory or line coiling.

The fly line coating—or rather, what a manufacturer adds to the fly line coating—also determines whether a fly line floats or sinks. Adding tungsten powder creates a dense line that sinks. Adding glass microspheres or gas bubbles makes a less dense floating fly line. Manufacturers can also combine these to make a line with a tip that sinks, and a floating body and running line.

Textures. While some companies go the extra mile making their lines as smooth as possible, Scientific Anglers has both smooth and textured lines. According to Scientific Anglers, the textured surface reduces friction because only the high points rub against the line guides, and textured lines float higher because of the way the texture creates contact points with the surface of the water.

Airflo lines have Ridge Tech 2.0, which is also a texture in the form of ridges running the length of the line. These longitudinal ridges also reduce the surface area where line contacts the line guides on the rod.

Tapers. There are two general types of fly line tapers: weight-forward and double-taper. Double-taper lines are economical and sufficient for most short- to medium-range situations, but have fallen out of favor with many fly fishers because they are not the best lines for making long casts. Double-taper lines are far more economical because the ends are symmetrical. Wear out one end and you can reverse the line on your reel, and in effect start over with a new fly line. Some fly fishers buy double-taper lines and cut them in half straight out of the box.

Weight-forward lines are the most popular type of fly lines for fresh and salt water. They have a narrow, level-diameter running line at the rear that shoots through the guides easily, allowing for longer casts of 50, 60, 70 feet and longer. They can’t be reversed like double-taper lines, so they are less economical.

A fly line’s taper directly affects the way it shoots, turns over a heavy fly, presents a small fly delicately, or casts efficiently at long or short distances. The line taper (its outside dimensions) is the result of varying thicknesses of the line coating—some parts are thicker and have greater mass, other parts are thin and have less mass.

This distribution of mass along the length of the line determines how the line performs in a variety of conditions. For instance, if you want the line to easily cast a wind-resistant bass popper, you need most of the line weight as close to the fly as possible. This additional mass, concentrated at the head of the line, helps turn over large flies during the final delivery. However, this is not ideal for fishing small flies on flat trout water, where you need a long, delicate tip for stealthy presentations.

Weight-forward tapers include nearly every specialty line, including lines made for bass, tarpon, steelhead, salmon, trout, and pike. If you want to make your casting as easy as possible and enjoy productive fishing, choose the specialty line that matches your situation. If you are fishing for trout, get a line advertised as a trout line. If you plan on fishing for bass, you will be frustrated trying to cast large bass bugs with anything other than a bass line. It isn’t just a marketing ploy—there are significant differences among the various specialty lines.

Color. Fly lines come in a rainbow of colors, from camouflage to dull olive to fluorescent green, orange, and purple. If you are just getting started, you should use a bright fly line you can easily see in the air and on the water. The easier it is for you to see your fly line, the easier it is for you to improve your casting and presentations. It can also help you locate your fly, detect strikes, and determine whether your fly may be dragging or not.

Trout can see colors in sunlight and in clear water, but most of the time color is far less important than a heavy splashdown, or the shadow caused by a moving line. This is especially true on most North American waters, where the clarity is not always perfect and there is often floating debris in the water.

Sinking lines. Trout, bass, steelhead, and other fish sometimes come to the surface for exciting moments of topwater feeding, but most of the time they skulk deep, feeding only occasionally on food items that come to them. Using a floating line is a pleasure, but if you want to catch fish regularly, you sometimes need to get down to them. In fly fishing, there are two common ways to do this: You can either use your floating line with a long monofilament leader and attach weight (split-shot usually) near the fly end of the leader, or you can use a sinking line and allow the weight of the line to sink the fly to the fish.

In shallow water 2 to 4 feet deep, a floating line with a weighted fly, or a fly with a split-shot attached 6 to 12 inches above it, works fine for both dead-drifted and swimming flies.

In moving water from 3 to 6 feet deep, you can effectively probe the bottom by dead-drifting flies with a weighted nymph rig. At this depth in moving water, streamers and other swimming flies tend to ride up too high in the water column unless you use an unwieldy number of split-shot. An alternative is to use a sinking or sinking-tip line.

As mentioned previously, sinking lines have tungsten powder in the line coating, which makes them denser than water. Sinking lines drop through the water at different rates, from intermediate 1.25 to 1.75 inches per second (ips) to fast-sinking 4.5 to 6 ips. Extremely fast-sinking lines sink as fast as from 7 to 10 ips.

Some sinking lines are marketed by their grain weight—300-grain, 400-grain, etc.—but don’t be fooled by the weight of the fly line. Grain weight helps you match the line to the rod, but the grain weight isn’t what makes fly lines sink—there are 750-grain floating lines, and 200-grain sinking lines. It’s the density of the fly line that causes it to sink, so match the grain weight to your rod weight and match the sink rate (in inches per second) to your fishing situation.

Full-sinking lines are best suited to fishing in stillwaters (lakes and ponds). They are designed to get flies down to the level where the fish are feeding, which could be 1 foot or 30 feet below the surface.

When you are fishing in shallows 1 to 3 feet deep, you may want to use an intermediate line to keep the fly where the fish are feeding while avoiding hanging up on the bottom. If the weather is extremely hot, and trout are holding in the cool depths of the lake, you’ll need a fast-sinking line to get down to them. An extremely fast-sinking line that sinks at 10 ips will take around 12 seconds to get the fly 10 feet deep, so you’ll have to use the countdown method: Cast, then count to 12 to get the fly where you want it.

Some sinking lines do not sink uniformly: The middle sinks faster than the thin, less dense tip, creating a U-shaped belly that can cause you to miss strikes. Most modern full-sinking lines sink uniformly to provide a straight-line connection to the fly, allowing you to detect a high percentage of strikes and thus catch more fish.

Sinking tips. Sinking-tip lines have a front sinking portion connected to a rear floating line. They are better in flowing water than full-sinking lines because you can mend and control the rear portion of the line while the tip sinks. Sinking tips range from intermediate to fast-sinking to bring the fly to the fish through a variety of both depths and currents.

The length of the sinking portion determines not how quickly the line sinks, but the final depth of the fly. Because the line sinks at an angle from the base of the floating portion to the tip of the fly line, a longer sinking portion gets deeper. For instance, a 30-foot sinking-tip section that sinks at 5 ips will get your fly much deeper than a 10-foot sinking section with the same sink rate.

Sinking tips are extremely important for West Coast steelheaders, who use them to swim flies slow and deep. Pacific salmon fall to the same strategies, and no angler should visit British Columbia or Alaska without a full complement of sinking-tip lines for 8- to 10-weight rods.

Striped bass fly fishers who fish off jetties and in deep tidal rips also require sinking-tip lines to reach the fish. Trout fishermen use them to “pound the banks” from drift boats and fish streamers in deep holes, and billfish anglers use the weight of heavy sinking shooting tapers to deliver extremely large flies quickly at short distances.

Studio photo of two spools of fly-fishing tippet — Scientific Anglers Absolute Trout - $8.95; Scientific Anglers Absolute Fluorocarbon - $16.95

Cleaner is better. Fly lines collect dirt, algae, and salt. A clean line floats higher, casts farther, mends more easily, and lasts longer since things like dirt and salt are abrasive.

Fly lines should be cleaned regularly using cleaning products sold and recommended by line manufacturers. Don’t use Armor All or any other general cleaner/protector, as the chemicals in these products can conflict with the composition of the line coating. Even if it feels slipperier right after treatment, it can have negative long-term effects on your line.

At the end of the fishing season, clean all your lines and wind them back onto their original line spools or store them in loose coils. Always store your lines out of direct sunlight. Ultraviolet light and heat can cause the line coating to deteriorate swiftly. Premium lines are more durable and last longer than cheaper lines. Under normal circumstances, a $130 fly line should last through about 100 days of fishing.

The longer you fly fish, the more fly lines you’ll accumulate. You’ll buy floating lines, sinking lines, lines for specific species, and of course different lines for different rod weights. The Scientific Anglers Regulator Spool ($30) can help you remove and neatly store fly lines when you are not using them.

Leaders and Tippet. At the end of your fly line you’ll need a leader. With sinking lines, you can use just a short section of monofilament. With a floating line, you’ll want to purchase a tapered leader that unrolls just like a fly line. The butt of the leader loops to your fly line, and the tip of the leader is where you attach your tippet. The tippet is narrow-diameter monofilament that allows your fly to drift naturally in the current.

Weight-Forward or Double-Taper?

A common question from new fly fishers is “Should I buy a double-taper or weight-forward line?” Double-taper lines were once the most popular fly lines for trout fishers because they work well at short to medium distances, they are easy to roll cast and mend, and most important because they are economical.

Since both ends of a double-taper line are the same, you can wear out one end of the line, then reverse it on your reel and have a “new” fly line. Since most double-taper lines are 90 feet long, you have a 45-foot end to work with. If you cast farther than that, you are using the other end, so there is some overlap.

Some old-timers used to cut their double-taper lines in half right out of the box, and use only a 45-foot line. This reasoning works fine on small streams where you rarely cast 40 feet, but as soon as you do that, you are limited in where and how you can fish.

Weight-forward lines are a large category that includes most specialty taper lines, which have one rear end and one front end. Most of the weight is near the front of the line, and the rear of the line is a thin level line called running line. They are by far the most popular fly lines sold today, and for good reason—they allow you to cast farther with less effort, defeat wind, and carry larger flies. Their only drawback is that you cannot reverse them. When the line is worn, you must replace it.

Do not believe the myth that double-taper lines somehow deliver the fly with more stealth, or that they have a more delicate front taper. A weight-forward line may have either a very long, delicate front taper for small flies on spring creeks, or a short, severe taper to turn over large flies. The main difference is that weight-forward lines have a running line at the rear. Double-taper lines do not.

Ross Purnell is the editor and publisher of Fly Fisherman.