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A Solid Foundation Builds the Perfect Fly

A Solid Foundation Builds the Perfect Fly
A carefully designed underbody is the signature of a polished and careful fly tier. If you want your flies to look like they were tied by a professional, start with flat, smooth tie-in points. (Photo by Charlie Craven)

Fly tying, like fly fishing itself, is loaded with infinitesimal details. I'm convinced that's why it attracts all of us. We like those details, and no matter how long you're at it, there is always more to learn.

I happen to be a detail-oriented kind of guy, and fly tying meshes perfectly with my borderline obsessiveness. To that end, I want to take this opportunity to write about some of the finer details in fly tying that are often overlooked, but can make a big difference in the functionality and durability of your flies, and make them look a lot better. Some people view these techniques as exclusively the realm of super picky classic streamer aficionados or Atlantic salmon fly tiers, but these techniques make even simple trout flies more polished, professional, and attractive.

Any successful creative process starts off with a good foundation. Michelangelo didn't sculpt David out of a block of sandstone, he used marble. Fly patterns are no different. True beauty comes from within.

Once you've selected the hook, your goal should always be to make a perfect fly pattern. All of this starts with the simple act of attaching the thread to the hook. This is your foundation. If you start your fly by building a poor foundation, you'll find it impossible to make a perfect fly. Maintaining a smooth thread base along the shank as the slim foundation for the tail and later, the body of the fly, requires knowledge, skill, and forethought.

I like to assure that the jam knot, as well as the initial thread base, is formed with flattened thread. By now my readers are familiar with unwinding the built-in factory twist in the thread to flatten it, after the thread is already on the hook, but that leaves a bump right at the start. [For more information on flat and round threads, and a complete treatise on the types of commercial threads available to fly tiers today, read "A Tangled Mess" by Charlie Craven in the Feb.-Mar. 2017 issue. The Editor.]

There are a few ways to flatten the thread before you start it on the hook, and doing any of them will help to form that clean, smooth foundation for tails and bodies rather than a coarsely corrugated thread base that is hard to anchor materials on.

To flatten the end of the thread, make a single turn of thread and, while holding the tag end, "rock" the thread back and forth against the hook shank by pulling up and down repeatedly on the bobbin and tag. This flattens the thread and allows you to form a smooth jam knot and thread base right from the beginning. (Photo by Charlie Craven)
You can also flatten the thread before you begin tying by running the first several inches of thread from your bobbin across the back edge of scissor blades. Flat thread forms a much smoother base and builds a slimmer core. (Photo by Charlie Craven)

My favorite method for flattening the thread starts by making a single turn of thread around the hook shank and rocking or sawing a length of thread back and forth to "push" the twist out. By flattening the thread in this manner, I form the smallest, smoothest jam knot and thread base possible. This smooth base makes it much easier to center the tailing material atop the hook shank and is the precursor to a smoothly formed abdomen.

Flat thread lies more smoothly along the hook shank than corded or twisted thread, and binds materials down over a wider area with fewer turns than corded thread. This means two flat thread wraps on the tail are all I need to hold things in place, and I don't need to build an unsightly lump along the hook shank to anchor the materials. When I think about it, lumps and bumps probably represent at least a third of all fly-tying troubles.

Another method that can be used to flatten the thread before attaching it to the hook shank is to run a length of the working end of the thread against the back edge of your scissors to push the factory twist out. You can even use your smoothly manicured thumbnail to do the same thing.

The idea is to start the thread as smooth and flat as possible so as not to build texture or bulk along the hook shankthis leads to a much easier process of building tapered underbodies and smooth tie-down points through the rest of the fly.

Once we have flattened thread started on the hook, there is still lots of work to be done. The shape and construction of the underbody is, in most cases, even more important than the final overbody. Overbodies using many hard materials such as wire, Super Hair, quills, and similar materials mirror the shape of the thread underbody, and even micro-thin dubbed bodies look better with a flat and smooth underbody. With this reasoning, you can see that a lumpy, bumpy underbody results in a lumpy, bumpy overbody and in all likelihood, an ugly, misshapen fly. Yes, I know they still catch fish. But it's not something you can (or should be) proud of.

Size & Symmetry

When building a tapered thread underbody, always downsize it a bit from what you have in mind for the outer dimensions of the finished fly. This accommodates the bulk of whatever overbody material you're going to use.

Think of the underbody as merely the skeleton and the overbody as the flesh and you'll get a pretty good idea of where you want to be.

Building a symmetrical underbody is the hallmark of a well-tied fly. Luckily, the overall balance is not thrown offgiven the scale of the thin materials we work witheven when materials are tied in along only one side of the hook shank. Conveniently, we are able to use the hook shank as the core of the fly and attach materials along the sides, top, or bottom without really throwing off the center balance.

What I mean to say here is, there is no efficient way to keep a fly pattern tied on a round hook shank completely symmetrical throughout the 360-degree radius of the hook, but there are ways to help keep things appearing that way.

One of the tricks I use to assure a more even underbody is to try to start my thread wraps where I want the abdomen to end. This gives me a blank hook shank to gather my proportion points from. That blank canvas, to me, just seems easier to gather where the exact midpoint, or 75 percent point, or "just a bit back from the hook eye point" really resides. From there, I start the flattened thread and wrap back to the bend, then tie in the tail on top of the shank.

Rather than cutting the butt ends of the tails off near the bend, I always wrap over them to the starting point (where the abdomen will end) to keep the hook shank a consistent diameter all the way along that length of the hook. I take pains to keep these butt ends on the top of the hook shank by using what I call a D-wrap.

D-wrap allows you to capture materials along the top or near side of the shank without letting them "crawl" due to thread tension. Execute a D-wrap by slightly lessening the tension on the thread as you bring it over the top of the hook shank and material, and then snap it tight in a straight motion across the bottom of the hook. (Photo by Charlie Craven)
The move travels in the path of a capital letter D, and causes the slack loop to close down abruptly over the material before it can be influenced by thread tension. (Photo by Charlie Craven)

The D-wrap loses a bit of tension as I come over and around the top of the shank and material, and then tightens in a straight line toward my chest across the bottom of the hook, forming the shape of a capital letter D turned on its side. Executing this technique takes a bit of practice, but mastering it allows for much cleaner tie-downs, and keeps materials in place with simple thread control rather than constant finger manipulation.

If there is a rib to tie in, I attach it from the front of the abdomen and wrap back over it, typically along the near side of the hook shankbecause I can see it most clearly thereall the way to the base of the tail. Again, this redundancy keeps the portion of the hook shank built up with the same amounts of wraps and materials all the way down its length.

If this is accomplished properly, I can tie in the body material or even wrap a tight strand of dubbing over a smooth, consistent-diameter thread base, and that helps me build a seamless, smooth overbody.

Attaching body material at the point where it will also ultimately end helps form smooth, symmetrical bodies without any lumps or bumps. (Photo by Charlie Craven)
Tying any hard body material in at any other point results in an uneven body, as shown in the second example. Your children and all generations after them will be disappointed in you if they see an errant lump caused by bad planning. (Photo by Charlie Craven)

It is little details like these that make the difference between nice flies and perfectly tied specimens you want to frame. Constant care and attention to the foundational wraps and construction of the underbody of any fly always results in a more cleanly tied and more durable fly pattern.

Smooth thread wraps form a more solid foundation for body materials, allow for smoother overlapping turns, and keep their shape better than tightly corded wraps of thread.

Additionally, in the case that you need a small application of Super Glue or some other type of adhesive or coating, a smoothly tapered and shaped underbody lends itself better than a lumpy, twisted mess you've been fighting with previously.

 Charlie Craven co-owns Charlie's Fly Box in Arvada, Colorado, and is the author of two books: Charlie's Fly Box (Stackpole Books, 2011) and Tying Nymphs: Essential Flies and Techniques for the Top Patterns (Stackpole Books/Headwater Books, 2016)

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