I've taught a lot of people to tie flies, and whether they are brand new tiers or even fairly experienced, one of the biggest troubles I see and hear about is fly proportions. It's not always easy to gauge exactly how long a tail should be or where exactly the wings should be placed on a dry fly, and sometimes it's tough to even have a really good idea of where the abdomen ends and where the thorax begins on a simple nymph. Even when you follow the best directions, you can still end up with a fly that seems strangely misshapen.
Luckily, there is a commonly accepted set of rules to follow for the length of things like wings, tails, and abdomens. Developing an "eyeball" measuring device to guide you can take years, but I am going to try here to give you the most commonly accepted guidelines, then some tips to make them easier to master, and finally some guidance on when to throw those guidelines out the window and break the rules a bit.
Nowhere are proportions more important than on upright winged dry flies. Proper wing and tail lengths produce a fly that is accurately sized to the hook — a functional benefit because proportions affect the balance of the pattern, and determine how it sits on the water. Wings that are too long can cause a fly to spin during the cast, or even to fall over once on the water. Tails that are too long or too heavy can change the perceived size of the fly significantly. These seemingly small details have a very large impact on how well the fly performs.
Perhaps just as important is that proportions help us judge the beauty and attractiveness of a fly. Just as a person with a large nose or small beady eyes might be considered ugly, a fly with a tail that is too long, or wings that are too short, is equally undesirable.
Also, universally accepted norms for proportions help to produce consistent flies. The "best" commercial flies are ones that all look identical. Even if you are not a commercial tier, the goal is always to produce "consistent" flies so when you have a row of Hare's-ears, for instance, they all look the same. Without proportions, you are shooting at a moving target.
Tip#1 Use a bare hook to double-check your measurements. Remember that a shank length and a hook length are two different things.
Tip#2 Sometimes it's necessary to overrun the abdomen to tie in materials such as a wingcase. Carefully wrap back to the correct starting position before dubbing the thorax.
Tip#3 A tight, clean shoulder at the end of the abdomen helps you make an accurate estimate of the abdomen length.
Tip#4 Start your thread where you anticipate the abdomen will end, and the thorax will begin. Use this spot as a marker.
Dry-fly tails are tied in exactly at the bend of the hook and extend one shank length beyond the bend. The density of the tail fibers is dependent on the overall dressing of the fly . . . more heavily hackled patterns have a thicker bunch of fibers for the tail while more sparsely dressed flies will have a correspondingly sparse tail.
Upright dry-fly wings are one shank length long and should be
mounted near the center of the hackle collar. Catskill-style drys tend to have the wings placed ever so slightly in front of the middle of the hackle collar while Western drys commonly feature wings placed more in the center of a thicker hackle collar. I attribute this to the notion that Western waters are more broken and faster moving than those in the East, and thereby require a fly with more hackle to float — although I am pretty sure there is also fast water in Pennsylvania.
Dry-fly bodies should occupy from 50 to 80 percent of the hook shank length, most typically ranging in the 60 to 75 percent area, leaving the remaining portion of the shank to be filled in with the hackle collar. As an example, an Adams could have a shank-length tail and wings, a dubbed body from the bend of the hook up to the 75 percent point on the shank, leaving the front quarter of the hook shank for the thorax/hackle collar. Placing the wings in the center of this front quarter of the shank would put them 12.5 percent of the shank length back from the eye and 87.5 percent of the way forward from the bend.
If that sounds too technical, just think of the wings as being in the center of the hackle collar, and your eyeball and brain will take it from there.(Make sure you account for that .5 percent I mentioned earlier or no fish will ever eat your fly. Ever.)
Downwings on drys (like an Elk-hair Caddis or Stimulator) should be no longer than one hook length long. A hook length is longer than a shank length and is measured from the front of the hook eye to the outside of the hook bend. A shank length is the distance from the back of the hook eye to the bend of the hook.
Sometimes downwings are tied in directly behind the hook eye, or in the case of a Stimulator, much farther back on the shank. As a general rule, the farther back the wing is mounted, the shorter it ought to be, and rarely should it extend past the tail.
Standard hackle on a dry fly should be one and a half to two hook gaps, although to my eye, hackle that is two hook gaps long looks gigantic. I nearly always shoot for a hackle length of one to one and a half gaps.
Consideration must be also be taken about where, and over what, the hackle is to be wrapped. Hackle wrapped on a bare shank looks shorter than the same feather wrapped over a dubbed abdomen. I usually downsize my hackle feathers by at least one size when wrapping or palmering them over a dubbed body.
Parachute hackle can be oversized by one hook size, although my personal preference is for parachute hackle that reaches from the wing post (at the 80 percent point) to the bend of the hook. René Harrop's beautiful and functional Biot Paraspinner in this issue [page 44] shows a great example of when and how to break those guidelines. While conventional wisdom is that the hackle on a parachute pattern imitates the legs of a mayfly, Harrop's fly instead uses the parachute hackle to imitate the long, spent wings of a mayfly spinner lying flush in the surface film, and therefore the hackle is purposely tied twice as long as normal to better match this identifiable trait.
Nymph tails should be tied in precisely at the bend of the hook and are usually one half to two thirds of a shank length. If tied particularly sparse, nymph tails can range up to a whole shank length in some cases — such as the RS2 — without changing the overall size and silhouette of the pattern. A thick tail bundle becomes an elongated extension of the abdomen, and can greatly alter the overall size and shape of the fly.
Nymph abdomens should take up 50 to 80 percent of the shank, leaving the remaining portion for the thorax. So if the abdomen is 60 percent of the shank, by default, the thorax occupies the remaining 40 percent. In my mind, anything that has an abdomen to thorax proportion of more than 80/20 becomes less of a thorax/abdomen and more of a body/head as is the case with midge or caddis larvae.
After a long diatribe like the one above, tiers usually say something like, "Okay, okay, we get it . . . but how do you do it every time?" Here are some hints.
Measure the wing or tail clump against the shank length before you tie it in. Use the edge of your thumbnail to mark the measured length and hold the material firmly at this point while you attach it.
Once you have the material tied in, measure it again. Use an exactly equal hook (same size and model) held in a pair of hackle pliers to re-measure the mounted tail or wing, and if it doesn't match what it is supposed to be, untie it and do it again. Practicing poorly and settling for "almost right" will never train your eye to what "exactly right" looks like. Measure it twice. Hell, measure it three times. Get it right so you'll know what "right" looks like.
Now, give it a sanity check. The shank of a standard size 18 hook is pretty short, and a half of that is shorter yet, so when you're tying a Pheasant Tail or any other nymph, take a look and see if that half of a shank length tail that you so precisely measured and tied in actually turned out to be half a shank or just "shorter" than usual.
Here's a great tip to ease proportional headaches on drys or nymphs. Plan ahead where the abdomen is to end on the shank, then start the thread at that point and wrap a thread base back to the bend. I find it much easier to get a good idea of hook proportions using a bare shank, so I always start my thread where the body or thorax should end. This leaves a clear indicator of where my abdomen needs to stop, as well as keeps a single smooth layer of thread under the abdomen.
A clean, tight strand of dubbing with a square shoulder at the front end will also contribute to an accurate measurement. Bodies that just sort of fizzle out make it hard to gauge exactly where they stop.
Sometimes, however, it's necessary to run the abdomen a bit farther forward than ultimately necessary to facilitate overlapping the wingcase and/or thorax onto its front edge, assuring that the two run together seamlessly.
There should be no gap between the abdomen and the thorax on a dry or nymph. Tying a feather slip wingcase onto the larger arbor diameter of the front end of the abdomen also helps keep the feather lying flat and prevents splitting. It's amazing how good technique begets good flies.
When trimming a wing to length, as in the case of an emerger pattern or parachute, accommodate the width of your scissor blade in your measurement. Your scissors cut at the center of their width, not the outside edge, and this small difference becomes important when you tie small flies. A poor cut can result in a wing that is forever slightly too long because your cut is farther forward than the outside of the blade. Just like with the table saw . . . cut on the outside of the line.
Hopefully these pointers shine some light on the dark side of fly proportions. As the old adage goes, "beauty is in the eye of the beholder" so if you're the only one who sees or uses your flies, feel free to make up your own proportions.
If, however, you really want to master the art of fly tying, and make your flies look "just like the ones in the fly shop," then try applying these simple tips for consistent proportions. The trout might not appreciate it, but you will.