** Note ** This Troutbitten article replaces one from 2019 about Seaguar Finesse. Seaguar halted production of Finesse in 2020, and after much searching, fishing and testing, along with the Troutbitten crew, I’ve landed on InvizX as my go-to choice for terminal tippet. Here’s why . . .
I was halfway into the canyon and at the tail end of a warm fall day on the river.
I found Sawyer standing above me on the tall bank, hands on his hips, smiling and satisfied behind his dark lenses.
“Well, how was it?” Sawyer asked without moving.
“Good!” I replied and pointed downstream. “I caught three off that far bank below, and a couple right next to this . . .”
“No. I mean the fluorocarbon,” he said.
“Oh,” I nodded. “Yeah, I’m sold! I’ll never nymph with nylon again.”
That was over a decade ago. Earlier in the day, Sawyer had given me his stack of fluorocarbon when I’d lost my own tippet holder spooled with nylon. Before that day, my skepticism and thriftiness kept me from buying in — from dishing out the $50 – $100 it would take to convert to fluoro. I thought I did just fine with nylon.
I did. And I’m still not so sure that flouro catches more trout under the surface. Some use it because it’s less visible and sinks a little better, but I use it because I have the chance to make more casts and keep my line in the water longer with fluoro. Here’s what I mean . . .
I use fluorocarbon for underwater presentations because the material takes more abuse. Its abrasion resistance and greater strength per diameter allows me to fish more aggressively against the structures where brown trout reside. Sure, I hang up, but I break off less. Flouro also has an uncanny way of releasing the inevitable twists and tangles of tippet that happen on a trout stream. Where I used to reach for the nippers with nylon, I now expect loose knots and loops to come out with marginal effort — and the few tricks of an amateur magician.
But let’s get back to me being cheap. I’m okay with that. I spend money where I must and cut corners where I can. And most long-term fishermen I know are the same. So the price tag of fly shop fluoro has always seemed a bit much to me, and I keep my ear to the ground for alternatives. For many years, my friends and I have used fluorocarbon that is marketed to gear fishers. We buy three to four times as much fluoro on a larger spool and then wind it onto small tippet spools. Years ago I settled for P-Line Halo, FC Sniper from Sunline, or Seaguar AbrazX. These were the best options among a host of other brands tried.
The trouble with these cheaper lines is threefold. Their breaking strength is inferior to the fly shop brands, they’re often stiffer, and the manufactured diameters only go down to about 4X — usually.
For a few years, Seaguar manufactured Finesse, and it was far better than the other big-spool fluoro options. It was my go-to choice for terminal tippet for a long time, and when Seaguar discontinued it, I felt a bit lost. Then Grobe told me he was fishing InvizX.
Matt Grobe is a good friend and Pennsylvania native now living in Montana. He chases big wild brown trout, mostly by nymphing them on a Mono Rig. Both Grobe and I agree that taking the fly to the trout is the most consistent way to catch the biggest fish in the river. Having them chase a streamer is fun, but I’ll put my money on an excellent nymphing or crossover approach most days. Grobe catches bigger, badder wild trout than anyone I know. So when he told me he was fishing InvizX, I listened.
Grobe uses Seaguar’s thinnest version of InvizX for his 5X. And now I do the same. But when I first saw the listed diameters and breaking strength, I balked, because I follow this stuff closely. Seaguar’s specs list InvizX .007″ as 4lb, but Matt assured me the line is underrated — InvizX is both thinner and stronger than it’s listed.
He’s right. I measured it to .0065″ and I estimate it’s breaking strength at about 5 lbs. (Stats on strength comparisons are below.)
InvizX is also softer, more flexible and has more stretch than most fluorocarbons, allowing the attached nymphs to move and wiggle at the end of the line. And that’s a good thing.
These days, a spool of fly shop fluorocarbon up to $20 for 30 yards. So getting 200 yards on a spool of InvizX for $20 is a steal.
In short, Seaguar InvizX has become my go-to fluoro tippet material in 5X, 3X and 2X. (I use Orvis Mirage or Cortland Ultra Premium for my 4X.) InvizX is exceptionally strong per diameter, and it’s flexible for a fluorocarbon. InvizX is as good as some fly shop brands, and it’s far better than many others. And because the type of tippet we use is not what catches trout, I don’t overspend on tippet.
** Note ** The above links are affiliate links. Meaning, at no additional cost to you, Troutbitten earns a commission if you click through and make a purchase (of anything — not just fluorocarbon). So, thank you for your support.
Breaking Strength Per Diameter
How strong is your 5X?
While it seams like a fair question, the answer is not that simple.
What’s printed on the label may not line up with the facts. Breaking strengths and diameters are notoriously inaccurate in our industry. (A twenty dollar micrometer quickly reveals this.) And while fly shop brands like to exaggerate their line’s breaking strength and under-list its diameter, fluorocarbon marketed to gear anglers trends in the opposite direction — breaking strength are often far more than listed in the gear world.
In the end, what matters for fly anglers is breaking strength per diameter. We want to get the most strength available in a very thin line.
Where’s the X?
You won’t find “5X” printed on any of these spools, because X ratings are a fly fisher’s thing. The thinnest line from Seaguar InvizX comes in at .0065″, which is right in between the diameter of 4X and 5X. Oddly, Seaguar’s own specs round up to .007″ instead of rounding down to .006″. And truthfully, this is what turned me away from giving InvizX a chance, until Grobe told me I was missing out.
The Tug-O-War Test
When I bought my first spool of InvizX, I was impressed with the handling — the flexibility — for a 100% fluoro line. (Orvis Mirage is similar this way.) With a better flex, the attached flies can move more freely, and they appear more realistic in the drift. That’s a good thing.
And when I fished the InvizX, I was surprised by its strength. Clearly, the breaking strength is more than listed. So I did a long series of pull-tests with other fly shop brands, going head to head to see which was stronger.
I used a Davy Knot and tied each line to the eye of a #14 nymph. I pulled, and recorded which line broke. I retied both knots and did the test ten times for each line. (This long testing process required two beers.)
The results below are obviously un-scientific. But the micrometer measurements are accurate. I also tie good knots, and the tests were performed without bias. Some of these results are surprising.
♦ Seaguar InvizX (.0065″) is stronger than Orvis Mirage (5X at .0059″). And they are equal in stiffness.
♦ Seaguar InvizX (.0065″) is equal in strength to Rio Fluoroflex Plus (5X at .0064″). And the Rio is stiffer.
♦ Seaguar InvizX (.0065″) is weaker than Fulling Mill Masterclass (5X at .0069″). And the Masterclass is stiffer.
♦ Seaguar InvizX (.0065″) is weaker than Cortland Ultra Premium (5X at .0067″). And the Cortland is stiffer.
♦ Seaguar InvizX (.0065″) is stronger than Trouthunter Fluorocarbon (5X at .0060″) And they are equal in stiffness.
♦ Seaguar InvizX (.0065″) is weaker than Trouthunter Fluorocarbon (4.5X at .0065″). And the Trouthunter is stiffer.
** These test results are only a comparison of InvizX to the other brands listed. They are here to give you some idea as to the relative strength of InvizX. This is not a full-range tippet shootout. And I’m not here to tell you what’s the best tippet available. A lot of factors go into that opinion, including cost, strength, diameter and flexibility.
Bottom line: I use Seaguar InvizX 4lb as my 5X, and it breaks closer to 5lb. I also like its handling and flexibility.
I use InvizX 6 lb for my 3X. And I use InvizX 8lb for my 2X. In my experience, all of them are much stronger than listed.
(I use Orvis Mirage or Cortland Ultra Premium for my 4X.)
No. There’s nothing smaller than 5X out there that I would buy outside of the fly shop brands. I had FC Super Sniper in its thinnest diameter, but I couldn’t trust it for my 6X.
So, I still buy 6X fluorocarbon in the fly shop brands. (I like Orvis and Cortland right now.)
My standard nymphing rig ends at 5X (because I don’t like leaving flies on the bottom of the river). But when I nymph with #18’s and 20’s, I often do better with 6X. So the name brand stuff is in my vest. But my primary nymph and streamer work happens with Seaguar InvizX.
I’ll mention this too: I continue to use fly shop nylon for all my dry fly fishing, and I don’t see an alternative for that any time soon. The supple high-end lines with greater breaking strengths are worth the nominal extra cost of fly shop nylon.
Seaguar InvizX comes on a bigger spool, of course. And that kind of inconvenience isn’t for everyone. I transfer the InvizX over to empty tippet spools, right out of the box. It takes about ten minutes and a couple of spools, but then I’m set for a good long time.
So if that sounds like something you don’t mind doing, try the InvizX.
Fish hard, friends.
Enjoy the day.
T R O U T B I T T E N