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Traditional dry flies float on hackle, stiff rooster feathers wound around the hook that hold the fly above the water's surface. The hackle creates dimples in the film that look, from a trout's perspective, like tiny legs pressing down on the water. The problem is that real mayfly duns don't have legs pressing into the film. They sit IN the film, their bodies flush with the surface, their wings upright, their legs barely touching the water. On pressured water where trout have been caught and released dozens of times, the hackle-on-the-surface profile of a traditional dry fly is a red flag. The fish eat the natural, refuse the artificial, and the angler changes flies six times before switching to nymphs in frustration.
The Comparadun and its descendant, the Sparkle Dun, solved this problem by eliminating the hackle entirely. These flies float on deer hair alone, a fan-shaped wing of hollow deer hair that splays in a 180-degree arc and supports the fly in the surface film. The body sits flush in the water. There are no hackle dimples. The profile, from below, looks like a real mayfly dun sitting on the surface.
This no-hackle approach changed fly fishing, and these two patterns, the Comparadun for general mayfly fishing and the Sparkle Dun for hatch-matching on technical water, have become the most important dry flies for selective trout in American fly fishing.
The History, Three Tiers, Three Decades
The story starts with Fran Betters of Wilmington, New York, who tied the Haystack in 1949, a simple fly with a dubbed body and a clump of deer hair tied upright as a wing. No hackle. The Haystack floated on the deer hair and caught fish on the Ausable River. It was ahead of its time.
In 1972, Al Caucci and Bob Nastasi refined the concept. They fanned the deer hair into a 180-degree arc (instead of Betters' upright clump), creating a wider footprint that floated better and presented a more realistic wing silhouette. They called it the Comparadun, a name from their book Comparahatch, which proposed matching specific mayfly species with specific patterns. The Comparadun had a split tail of hackle fibers or microfibbets, a dubbed body, and the fanned deer hair wing. No hackle. It was revolutionary, a dry fly that sat in the film like a real insect.
In 1983, Craig Matthews of West Yellowstone took the Comparadun one step further. He replaced the split tail with a trailing shuck of Z-Lon or Antron yarn, a few strands of sparkly synthetic material trailing behind the fly to imitate the nymphal shuck that a mayfly dun leaves behind when it emerges. He called it the Sparkle Dun. The trailing shuck was the insight that made the pattern deadly: trout don't just eat adult mayfly duns, they preferentially eat emergers, insects still partially trapped in their shucks, because emergers can't fly away. The trailing shuck tells the trout "this insect is vulnerable," and the trout eats it with confidence.
The Sparkle Dun became the go-to pattern on the Henry's Fork, the most technically demanding dry-fly water in America, and from there it spread to every selective-trout fishery in the country.
What They Imitate
Both patterns imitate mayfly duns (newly hatched adults) sitting on the water surface:
- Comparadun: A generic mayfly dun, upright wing, body in the film, no hackle. Works as both a hatch-matcher and a searching pattern.
- Sparkle Dun: A mayfly dun still trailing its nymphal shuck, the emerger stage, when the insect is most vulnerable. More specific than the Comparadun and more effective on selective fish.
In practice, the Sparkle Dun has largely replaced the Comparadun on technical water because the trailing shuck is the detail that matters most to educated trout. The Comparadun remains excellent as a general-purpose mayfly pattern on less pressured water.
Both patterns can be tied to match any mayfly species by adjusting the body color and size:
- PMD (Pale Morning Dun), #16-18: Pale yellow body. The PMD Sparkle Dun is the single most important fly on the Henry's Fork Ranch and Livingston's spring creeks during the June-July PMD hatch.
- BWO (Blue Winged Olive), #18-22: Olive-grey body. The BWO Sparkle Dun is essential for the fall and spring BWO hatches on every tailwater and spring creek, including the Green River and the Driftless Area.
- Hendrickson, #12-14: Pinkish-tan body. Eastern hatch.
- March Brown, #12-14: Tan/brown body. Early-season hatch on Eastern and Smoky Mountain streams.
- Sulphur, #16-18: Pale yellow/cream body. Late-spring hatch across the East and Midwest.
- Green Drake, #10-12: Olive body with cream accents. Sporadic Western hatch on rivers like the Henry's Fork.
- Callibaetis, #14-16: Speckled grey body. Stillwater and slow-river hatch.
The Recipe, PMD Sparkle Dun
| Component | Material |
|---|---|
| Hook | Standard dry fly, #12-22 (TMC 100, Dai-Riki 300) |
| Thread | 8/0 pale yellow or olive (UTC 70 Denier) |
| Trailing shuck | Amber or tan Z-Lon or Antron yarn (sparse, 6-8 fibers) |
| Body | Fine dubbing, Superfine or equivalent in the matching mayfly color |
| Wing | Comparadun deer hair, fine, straight, evenly stacked, fanned 180° |
No hackle. No tail (the trailing shuck replaces it). The wing IS the flotation.
The Recipe, Standard Comparadun
Same as the Sparkle Dun, but replace the trailing shuck with:
| Component | Material |
|---|---|
| Tail | Microfibbets or hackle fibers, split into a V (8-10 fibers) |
Everything else is identical. The choice between Comparadun and Sparkle Dun is the choice between a split tail (general mayfly dun) and a trailing shuck (emerger).
Where to Fish Them
These are the patterns for selective trout on technical water, the flies you reach for when the Parachute Adams gets refused:
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Henry's Fork, Idaho, The Sparkle Dun's home water. The PMD Sparkle Dun (#16-18) is THE fly for the Railroad Ranch PMD hatch from mid-June through August. When Ranch trout are refusing standard hackled patterns, the Sparkle Dun's flush-in-the-film profile is often the answer. Craig Matthews designed it for this exact situation.
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Livingston, Montana, PMD Sparkle Dun (#16-18) during the June-July PMD hatch on DePuy's and Armstrong's. BWO Comparadun (#18-20) during the fall BWO hatch. These spring creek fish are among the most selective in Montana, and the no-hackle profile outperforms hackled patterns consistently.
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The Green River, Utah, BWO Sparkle Dun (#18-22) during the March-May BWO emergence on Section A. PMD Comparadun (#16-18) during the summer PMD hatch. The Green River's educated fish respond to the trailing shuck.
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The Driftless Area, Wisconsin, BWO and Sulphur Comparaduns (#16-20) during spring and fall mayfly activity on the spring creeks. Less technical than the Western spring creeks, so the Comparadun (without the shuck) often suffices.
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Great Smoky Mountains, North Carolina, March Brown and Sulphur Comparaduns (#12-16) during the spring mayfly hatches. The Smokies trout are less selective than Western fish, but the no-hackle profile still outperforms hackled patterns on the glassy pools.
How to Tie Them, Video Tutorials
The critical skill is the deer hair fan wing. The hair must be stacked (aligned tips), tied in at the thorax, and fanned into a 180-degree arc that supports the fly. It's an intermediate technique that's easier than it looks once you understand the mechanics.
For beginners: Fly Tying for Beginners: The Sparkle Dun, Clear, slow instruction focused on the deer hair wing technique.
PMD version: Sulphur/PMD Sparkle Dun Tying Tutorial, Detailed walkthrough for the most important color variation.
Comparadun specifically: Comparadun Fly Tying Tutorial, The split-tail version with the deer hair wing. Good comparison to the Sparkle Dun.
Tips From the Vise
Deer hair selection is everything. Use comparadun-specific deer hair, fine, straight, and uniform in length. Nature's Spirit Comparadun deer hair is the industry standard. The hair must stack cleanly (aligned tips in a hair stacker) and fan evenly around the hook. Coarse or curly deer hair won't fan properly and the fly will land on its side.
The tie-in point determines the wing angle. Tie the deer hair in at the midpoint of the hook shank, halfway between the eye and the bend. Position the thread wraps so the hair fans backward at about a 90-degree angle to the shank. If the wing tips forward, the fly won't float upright. If it tips too far back, the fly will land tail-first.
Less shuck, not more. The trailing shuck on a Sparkle Dun should be sparse, 6 to 8 fibers of Z-Lon, extending one hook-shank length past the bend. Too much shuck creates drag and makes the fly look like it's trailing a parachute. The shuck should be barely visible, a subtle suggestion, not a neon sign.
The body must be thin. Like the Parachute Adams and the Pheasant Tail, the Comparadun/Sparkle Dun body should be slim, a gradual taper from the shuck to the wing. Overdubbing sinks the fly because the deer hair wing can't support the extra weight.
No floatant on the shuck. Apply floatant to the deer hair wing and the body, but NOT to the trailing shuck. The shuck should sink slightly below the surface film, that's what makes it look like a real nymphal shuck trailing behind an emerging dun. A floatant-coated shuck rides on the surface and loses the effect.
Build Your Box
Tie a dozen PMD Sparkle Duns in #16 and #18, the most important mayfly match on Western spring creeks. Add a dozen BWO Sparkle Duns in #18 and #20 for fall and spring BWO hatches. Tie a half-dozen Sulphur Comparaduns in #16 for Eastern/Midwest fishing and a half-dozen March Brown Comparaduns in #12-14 for early season. Total: about 55 flies, fewer than nymph patterns because you use them more carefully. Two evenings at the vise.
