The Fly Line Nerd Out – Part 1: The difference between weight-forward and double taper fly lines

The Fly Line Nerd Out  – Part 1: The difference between weight-forward and double taper


In the shop it’s a question asked often, what’s your favorite fly line? Besides being questioned about the “best” fly rod it’s an inquiry we receive on countless occasions throughout the year. Just like fly rods I believe there is a proper tool for the job when it comes to almost every fishing situation. For this blog on-going blog I will be discussing all sorts of fly line topics.  Within the industry it’s become quite the task to understand every single new fly line that comes to the market.  In this post I will be starting with the basics by discussing the difference between weight-forward and double taper lines. To help further the discussion I will have Kyle Shea from Deneki Outdoors to assist us in this matter.  Also included will be one of my preferred lines and I have gathered snippets from two of my favorite fly fishing industry friends to include throughout this article. In general this blog will give you a better understanding of fly line design as well as some knowledgeable insight into different lines and preferences.


When fly line decisions have to be made, understanding fly line design, and different tapers will help formulate better decisions and provide a more enjoyable casting experience. I’ve asked Kyle to provide a quick synopsis when it comes to down to it:


“Whenever discussing fly line design, I always think it’s helpful to define what a fly line actually does. First and foremost, a fly line provides the appropriate weight required to bend the rod during the cast. This can be achieved regardless of taper. Secondly, by providing weight capable of bending the rod, the fly line allows virtually weightless flies to be delivered to fish with tools strong enough to fight the fish being targeted. It also does so with a particular ‘presentation’ in mind, the goal of which is almost always to transmit just enough energy to turn over appropriate flies and leaders, but dissipate just enough energy for as subtle a presentation as possible. Finally, a fly line is meant to be fished, and that opens up an entire discussion on how well it needs to float, sink, mend, etc. for the fishery at hand. These three fundamentals are what dictate my favorite fly lines for the fisheries I fish most. Although I fish primarily weight forward lines, my favorite fly line tapers typically feature the benefits associated with both weight forward and double taper lines.”


Now that you can better understand fly line design let’s look at the two most common fly line tapers in the industry which are WF(weight-forward) and DT(double-taper).  Manufactures tend to deal with more weight-forward designs because they load modern graphite rods better which makes for easier casting. The WF lines you will find on the shelf at Fishwest are designed to help any angler turn over longer leaders and punch bigger flies through the wind. These lines accomplish all this by simply having more of the weight of the line towards the “head” or forward part of the line. Looking at the example below of an Airflo Xceed WF taper the head length is 38 feet which holds the majority of the lines weight. All WF lines have a thin running line that goes into the rear taper which forms the head of the line consisting of a rear taper, front taper, and a belly between the two.

For the most part the WF(weight-forward) lines are generally the most used/fished fly line in the industry. The fact is a WF line is easier to cast on today’s modern graphite rods and doesn’t have much of a downside. The only real disadvantages to a WF line are its inability to throw dry flies with a delicate presentation and they can be too heavy for slower action rods. WF lines come in a variety of shooting heads and can also be a half-size heavy. For example a 5WT line is actually a 5.5WT line that has more grain weight then industry standards. These half-size heavy lines are perfect for most modern graphite rods which tend to be fairly fast action. The standard “true” line weight for a 5WT rod is 134-146 and some of the half size heavy lines in today’s market can weight around 150-160 grains. Choosing to use a half size heavy line is recommended for faster action rods. Avoid over-lining any slower action rod because it can make casting difficult and can dramatically decrease accuracy. There are very few instances where you will want to put a 6WT line on a 5WT rod for example because half-size heavy lines have been designed specifically for modern fly rods.  When the occasion calls for it, wind and big flies mostly, I like to over-weight rods. For musky and an upcoming trip to chase Roosters I use a 10WT rod with a whole size heavy line, essentially an 11WT line to make casting at a distance much easier.

Covering the other side of the taper spectrum DT or double-taper lines have all the traditional action rods and dry fly anglers covered. When I was younger the DT lines were the most familiar. For various reasons DT lines have slowly become less popular mostly due to revolutions in rod building materials and design. Most rods as stated above tend to be faster action graphite rods as opposed to bamboo or fiberglass. Essentially double taper lines are best used on slower or more traditional action rods. I like to use DT lines on smaller fiberglass rods like the Echo Smallwater Glass 4WT. When using similar glass rods I’m probably fishing smaller water with dry flies and for that reason I choose DT lines.  In the example below you can see the line is designed to have the weight evenly distributed throughout the entire fly line.

The taper is the same on both ends which allows for easier thrown delicate presentations, roll casts, and excellent mending. My favorite part of a double taper line is it gives me the ability to cast a variety of loops with little effort. Fishing a fiberglass rod with a DT line is perfect for small creeks and dries because you don’t need a ton of line out to load the rod. This can be the only major downside of DT lines because they are not very effective in windy conditions but also depends on the rod and size. The weight and slower line speeds are just not enough to punch through a strong headwind. The running line on a WF line is much more aerodynamic and is better for windy days. Luckily, when I’m using DT lines I’m usually not casting long distances and only have so much use for tight laser-style loops.

When it comes to fly fishing most anglers have a use for both WF and DT lines. Depending on the rods in your arsenal there is still a multitude of lines to choose from. To help you make a more informed decision I have included one of my favorite lines as well as some information from three of my favorite people in the industry: Jeremy Inman(Alaskan Guide) and the Harkins brothers(Industry Reps).


Jeremy’s quick take on fly lines:

Almost anyone who fly fishes has gone into a fly shop at some point and browsed through a massive selection of fly lines and seen the WF on the label. Most of you also probably already know it stands for “weight forward”. It’s the most standard fly line style for trout fishing as well as other fishing applications. But not all WF fly lines are exactly the same. There’s a right tool for every job, and understanding the fly line will make your time fishing more enjoyable as well as more productive.

There’s a lot of variety to be had fishing in Alaska, no fly line can do it all, but there are some fly lines are better at covering more bases than others. The fly line I use the most on a daily basis is the Rio Indicator II.  As you could guess, I spend a lot of time with clients fishing indicator rigs with beads and flesh patterns, and that’s where this fly line excels. The fishing is far less technical than in other places and a lot of the time the name of the game is getting the fly deep and covering water. It has a mellow taper allowing for excellent line control, mending at a long distance, and long distance hook sets, which is where more aggressively tapered indicator lines tend fall short. The Rio Indicator II is a great all around fly line if you’re looking for maximum control over long hero drifts, small streamers and mice. It doesn’t turn over large heavy flies or sink tips very well, and it does have a bit of stretch too it. Overall I get about 3 months worth of fishing all day every day out of the line before it’s time to be replaced.

Now when it comes time to hit a back channel or a small tributary, there’s no need to change to a different line just because you want to throw something different. Which is ideal, because when my boat has four clients in it, it’s usually not practical to bring 12 different rods to meet every situation. While the Indicator II won’t turn over big sink tips or giant weighted bunny leeches for silvers very well, in small stream applications it performs just fine. It’s more delicate than some short tapers (like the RIO Grand for example) and makes it easy to be accurate and deliver a mouse or sculpin softly against the bank or against a log jam of a small stream without spooking fish. The Rio Indicator II is a great all around fly line if you’re looking for maximum control over long hero drifts, small streamers and mice. It doesn’t turn over large heavy flies or sink tips very well, and it does have a bit of stretch too it. Overall I get about 3 months worth of fishing all day every day out of the line before it’s time to be replaced.

Now the Harkins brothers probably don’t shred through lines like an Alaskan guide but they still have some great insight into the world of fly lines. I sat down with both of them and asked about their take on tapers and one of their favorite lines, here is what they had to say:

Chad:  Personally, I’ve never really explored double tapers and have stuck with WF for the fresh and salt.  I’d guess most rods nowadays are designed and tested for WF lines.  I like the progressive “shooting head” taper of the WF…it loads great and I feel like the thinner running line is easier to carry at longer distances with fewer false casts, tighter loops, and faster line speed (not to mention more capacity for backing).  Honestly, I don’t have a favorite fly line, as most manufacturers make great lines.  I’m currently fishing Rio Gold on my fresh setups and Scientific Anglers Bonefish taper on the appropriate saltwater setups. Although I’m a WF guy, it’s nice that a Double Taper basically provides two fly lines…wear down one end of it, and you can just switch it!

Scott: Weight forward lines have evolved from being clumsy, with non delicate presentation to complex tapers designed for various fishing techniques.  Double tapers have almost become obsolete, the old theory being that an angler can turn his line around to double the life.  I don’t think anyone is really doing that anymore.  There are so many great WF lines on the market and for trout, I’m currently enjoying the Scientific Anglers Amplitude MPX.  In Saltwater, I really like the Scientific Anglers Grand Slam and Rio’s Flats Pro lines.

For part 1 of this series I have chosen to highlight my favorite dry fly line which is the Airflo Super-DRI Bandit. This WF half-size heavy line is a slayer on a 5WT rod with bigger dry flies, poppers, and even soft hackles. This line features a twelve foot tip of “camo bands” to help break up line profiles for stealthy presentations. I’ve used this line with shorter leaders on technical fish and had enormous success. The long rear-taper keeps the line stable, propels through the air, and stills allows for a nice subtle presentation. While visiting Idaho on a week-long trip throwing big foam bugs this line made my inner nerd giggle with fly fishing joy!

Stay tuned for Part 2 where we will divulge more into other tapers, some of Kyles favorite lines, and hear from more fly fishing friends and industry professionals.