antron yarn

Guest Blogger: Michael Vorhis, author of ARCHANGEL suspense thriller, OPEN DISTANCE adventure thriller & more to come 

We see recipes for this fly or that, calling out a variety of exotic materials, usually claiming that the ones most difficult to find are the most critically necessary to a wily fish's eye. This is especially true for trout flies, given that so many other species appear triggered more by color and motion than by the differences between how an Australian Possum and a Fur Seal chose to evolve their fur.

It's less common to come across synthetic materials said to be simultaneously magical and scarce. One that comes to mind is the so-called "Utah Killer Bug" yarn, Chadwick's 477, around which has grown a kind of mythologic reverence since the day Frank Sawyer popularized the pattern. Despite the demand for it, this yarn can no longer be found (probably because Chadwick was into sweaters and not trout flies). And so the best substitute is said to be Jamieson's Shetland Spindrift Oyster 290, which anglers in the know claim MIGHT be ALMOST as good, translucency-wise and wet-color-wise, as the revered Chadwick's.

Another is a type of fly tying yarn we can get readily from J. Stockard in many colors, but once upon a time you could buy skeins of it in Wal-Mart. It’s Antron. A decade ago a fistful of Aunt Lydia's Heavy Rug Yarn, Antron flavor, would last you ten lifetimes. But don't bother trying to find such skeins now, on auction sites or wherever, because rugs have long since gone to other cheaper fibers. Get it from J. Stockard in a less ridiculous size. 

heavy rug yarn
Dear departed Aunt Lydia​​

Many questions beg to be answered: Why are we so particular with these synthetic fly tying yarns? Why this fiber or that? It’s because property-wise they're very different. I'll describe five different kinds of common yarn and tying fibers: 

Types of Fly Tying Yarn


This fiber is easier to find than cotton. It's used for everything from carpets to hats. With a specific gravity of about 1.4, it’s significantly heavier than water (which by definition has an SG of 1.00000). An SG of 1.4 means that, other than surface tension effects, wetted polyester sinks fairly quickly and is unlikely to hold up the weight of a hook for long. It can be pretty fine--some synthetic wetfly dubbings include (or are entirely) polyester. 

polyester yarn
Polyester Yarn​​

The fibers are usually round or have irregular cross-sections (although three-armed “trilobal” polyesters do exist, found among specialty embroidery threads). The surface of some polyester fibers can be smoother than others (“multi-fiber” being usually smoother than “spun”), but most polyester tends to lack the reflectiveness of some other synthetics. In part because of that, a fly body made of loosely & sparsely applied fine polyester can sometimes appear semi-translucent, letting more light pass between its fibers than is rejected back at the eyes.

Many--perhaps most?--egg fly tying yarns have a high polyester content. The fiber is ideal for this purpose; colors can be great and reflectivity is not what’s desired.

Other common fibers such as rayons are weaker than polyester and lack qualities fly tyers seek. Polyester fibers can be soft, although not as soft as nylon. While day-savers in a pinch, polyester yarns can be lack-lustre (pun intended) substitutes for more amazing fly-tying yarns.

Polyester is NOT what fly-tiers mean when they refer to "poly yarn”--they’re referring to polypropylene...


Skeins of poly-pro (or imprecisely called "poly" by many) yarn aren't easy to find at all, per my experiences. In fact I've never managed to find a skein. It can be obtained from J. Stockard in fly-tying quantities, but in large mass-market lumps I doubt it exists to the private tyer. Polypropylene twine, as opposed to yarn, can be found in hardware and even 99-cent stores; it's a very cheap string to make and is used as plumb-bob string and general purpose packaging twine. Despite it being a bit ratty-looking, I've used 6-inch sections of it (with a loop on each end) between floating fly line and leader, as a high-vis never-sinks-unless-pulled-under "tip" that acts as a sort of indicator while also still acting line a line--good flotation and visibility properties but no bobber and no real "kink" in the line's path. 

Offering a specific gravity of only 0.9, this synthetic floats readily, and so it's used as parachute posts and dry fly or spent-spinner wing material, and in some patterns (such as large adult insect imitations) it’s a good floating body material too. There are dry fly dubbing products made entirely of polypropylene. 

Polypropylene twine
Polypropylene T​​wine

Polypro would not absorb water if it were submerged for a week. It has a dull sheen, or none. Its uses for tying flies are rather specific, but what it does it does very well. 

Streamer Synthetic Fly Tying Yarn

I almost called these “plastics” but I didn’t know what most are made of (and in fact a “plastic” is really any synthetic that stores energy poorly when deformed). There are a world of synthetic streamer fibers, right on through to “tinsels” like Flashabou and Krystal Flash. To my knowledge none of them float. They’d be the subject of a different kind of article. 


Also spelled "Z-Lon" in some packaging (such as on the Umpqua site...from Metz and other merchants who I suspect obtain the raw stuff from Umpqua), this material is a type of nylon, slightly heavier than water (an SG of roughly 1.2), similar to Antron but typically crinklier (at least the classic stuff is...although now there’s “straight Zelon” too). Being nylon, it is thickness-for-thickness softer than polyester and stronger as well. Zelon doesn’t further soften with water absorption (or not measurably by an angler’s standards). So wet or dry, it won’t clump--it doesn’t mat together and it holds its shape. Being a fiber of “trilobal” cross section (more on that later), it is much more reflective than polyester, and is somewhat translucent as well...but it’s still without a contiguous “sheen.” Even so it possesses a pleasing lustre and is highly visible in a wide range of light intensities. 

In 1985, Blue Ribbon Flies of West Yellowstone, Montana (John Betts and I believe Craig Matthews too) purchased the world’s supply of raw Zelon from inventing company DuPont. Since then it can only be acquired through BRF or Umpqua (who clearly partners with BRF for Zelon/Z-Lon distribution). 


Zelon is versatile. Its high visibility makes it excellent for parachute posts, some segmented bodies, trailing shucks, and more. Anything that benefits from kinky/wavy high-vis fibers that are easy to tie and that need to hold their shape can be addressed with Zelon.

I find it so much easier to use than slippery materials such as calf hair that I greatly prefer Zelon for "hair" wings, for example for Wulff dries and other similar patterns. Its kinked nature fills volume with comparatively few fibers, so “wings” can be simulated with minimal weight.  

“Micro-Zelon” now exists too--it's very fine, but otherwise exhibits Zelon’s unique properties. 


And finally we come to the one I personally consider the Belle of the Ball. Antron is so often described by manufacturers as being "good for tails and trailing shucks." What a classic example of weak understatement! Don't do what I did for some years, substituting whatever I had on hand instead of stocking Antron; this stuff is to die for. The first time I tied with it, I was amazed that I'd gone so long assuming I could just use other nylon fibers...or polyester, like the el cheapo flies use. In fact I was amazed that this stuff is not reserved for the evening gowns of royalty, with that comparatively ugly trash called "silk" being tossed down to the likes of us.

Antron is nothing short of beautiful. Stunning. The word "sparkle" doesn't begin to capture the truth; it catches the light in magical ways that draw trout out from under their root-tangled banks. It comes in multiple colors, including the original fine clear variety. It’s soft to begin with, and when wet softens further and takes on the look of pure natural silk. Once I got hold of some, I put the flies I'd tied with substitute fibers in a separate fly box, vowing to cast them into trees in hopes of losing them as quickly as could be managed.

Like Zelon, Antron is a Dupont nylon, with a specific gravity of about 1.12, so it’s a little heavier than water. It was used for quite awhile in the rug and carpet industry, not only because of its durability but because it combatted dirt by reflecting a lot of light and appearing squeaky-clean. It eventually gave way to polyester fly tying yarns (which are also sufficiently durable but cheaper), and dear Aunt Lydia stopped being our prime supplier. But no matter; Danville and Hareline (and probably others) market spools of it, and Hareline also markets packets, which I find easy to use without wasting any and which make it easy to blend several colors by hand. J. Stockard has an excellent selection at great prices. 

Fly-tying Antron fibers are comparatively fine--and softer than Zelon, yet surprisingly durable. They too are fibers of “trilobal” cross section, which means they have a treble-lobe shape. The multiple lobes allow much more light to be reflected than from other fiber shapes--internal reflections are a big part of the effect. 

antron for sparkle emergers
Antron for Sparkle Emergers​​

The trilobal shape is not unique to Antron/Zelon; there are others (even some polyester). What makes Antron different even from other trilobals is its softness, its fineness, its ability to absorb water, its flow, its glow, its sheen. When wet, the fibers hang onto each other and work together. It is said, even by the marketeers of Zelon, that one should think of Antron when thinking of silk. Quite an accolade.

Antron’s list of uses has no end. Many spin it into other dubbings, even natural dubbings that themselves have legendary UV properties; the Antron adds a captivating quality that plays with any light. Yes, tails...yes, trailing shucks (really good for this, in fact)...but being much softer than Zelon and being hydrophilic (drawing water in as opposed to repelling it), it flows with the current when trailing streamers, wetfly wings, and longer tails can benefit greatly from it. It's generally not used as a parachute post due to its softness; but it is chopped and touch-dubbed for fly abdomens. Perhaps the best examples of fly patterns that utilize all its fortes are the legendary La Fontaine Sparkle Pupa and Sparkle Emerger. It is in tying these that those without Antron in their kit will finally realize their long-standing folly.

The old rug-yarn Antron is still used by some streamer tyers who were smart enough to stock up when the gettin’ was good (or who may know a yarn-skein source the rest of us don’t), but the trout-fly Antron products of today still are said to have a finer fiber. But note that you can order a packet of fly-tying Antron in Color X, and love it, and want more...but ordering another packet of the same color won’t necessarily get you the same color. Repeatability seems to be lacking with enough frequency that it’s worth mentioning; just don’t be surprised. I think it may be because fly-tying suppliers are at the mercy of larger industry (such as carpet) demand, but that’s just one guy’s wild guess.

Antron is often mixed with natural fibers to make high quality dry fly dubbing--it spins well on a thread, mixes well with many fibers, and adds that magical silky sheen.

The fibers described above all have their uses. Being masters of detail, we're accustomed to not only substituting as needed but also--and preferably--to recognizing and utilizing the perfect material for a given intended effect. I consider Antron and Zelon the dynamic duo, the tag-team champions, dual rightful wearers of the synthetic fiber crowns. On my vise, anyway. 

Properties & Common Uses

Synthetic Fiber Properties Common Uses
Antron Slightly heavier than water; silky sheen; fine; soft; strong; fibers mat when wet; highly reflective; mixes well with other fibers (both natural and synthetic) Pupa cases; tails; wetfly wings; body dubbing; other reflective sheen needs
Zelon (Z-Lon) Slightly heavier than water; a bit crinkly (classic variety); holds its shape; great visibility; flexible; ties easily Trailing shucks; upright wings; parachute posts; segmented bodies; other (as the varieties allow)
Polypropylene Floats very well; lightweight; durable; won't absorb water; flexible; ties easily; can be highly visible; can have soft shine Dry-fly & spent-spinner wings; large adult fly bodies; parachute posts; other floating needs
Polyester Notably heavier than water; fibers can be fine; no significant reflectivity or sheen; mixes well with other fibers Dubbing for flies that don't want to be reflective; egg flies; on-hand substitute; yarn-bugs (e.g. "Utah Killer Bug")

I hope this article provides a one-stop de-mystification for these important materials. 

1 comment

Fred DeFelice

Fred DeFelice

This is a great article and I find it very helpful. I will post this info on my tying desk. Thanks

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