While fluorocarbon leader and tippet materials are no longer a new discovery in the fishing scene, lots of us are still uncertain of the difference between newer fluorocarbon and traditional nylon monofilament. If you are in this category, before stocking up on tippet spools for the coming season, keep reading and we’ll try to clear up the differences between the two.
First off, don’t be fooled by the substantially higher price tag on fluorocarbon materials when compared to monofilament. Many anglers reach for fluorocarbon under the assumption that because it is more expensive, it is a superior choice of line. While there are many superior qualities of fluorocarbon, both fluorocarbon and monofilament have their place depending on the situation. The higher price of fluorocarbon is as much a result of the manufacturing process as it is the “fishing value.” When comparing leader and tippet materials, there are a few qualities that are of utmost importance – read on.
Visibility
The visibility, or better put, the “invisibility” of fluorocarbon line is most likely the best selling point of fluorocarbon when compared to standard nylon monofilament line. The light refractive index of fluorocarbon is very similar to that of fresh water (much more so than monofilament). In other words, when placed in water, it is less visible than monofilament.
Not convinced? You can see for yourself. Take strands of equal diameter of both fluorocarbon and monofilament and dip them in a glass of water. Notice the difference in transparency of the materials in water.
Strength
When talking about strength, there are several dimensions to consider. In the short term, fluorocarbon is a much harder material than monofilament. This results in higher abrasion resistance that is useful in situations such as nymphing or fishing around heavy structure. Also, most fluorocarbon line is thinner in diameter than monofilament line of the same breaking strength. However, this is not always the case from company to company.
Fluorocarbon is also non-permeable to water and therefore does not absorb water throughout the fishing day. This may not seem like a big deal but most do not realize how much water nylon monofilament actually absorbs throughout the day. Over time, this causes monofilament to weaken.
Over the long term, fluorocarbon is extremely resistant to the elements as well, unlike monofilament. Overtime, U.V. rays, rain and humidity, and extreme temperatures (both hot and cold) can cause monofilament to break down and lose strength. Fluorocarbon is much more resistant to these conditions over the long term. For most of us, these conditions are the norm during a fishing day. This is worth considering before pulling out that dusty tippet spool you bought on sale two years ago.
On that note: due to the fact that fluorocarbon does not break down very readily, please take care when disposing of it. Any pieces clipped off and thrown into the river will be there for a very, very long time.
Density
For you trout fisherman out there, the density of your leader material is actually very important. Fluorocarbon is actually denser than water. In other words, it sinks. This is great when dredging the bottom with nymphs or stripping streamers. However, if dead drifting or skating flies on the surface, this is the last thing you want. Nylon monofilament on the other hand actually suspends in water. If fishing dries, especially in very small sizes, monofilament is a clear winner here.
Stretch
Most anglers are aware that monofilament is a relatively “stretchy” material. Just grab your leader from both ends and pull; you will see it stretch. While a certain degree of stretch is advantageous to help absorb the shock while fighting a fish, less stretch results in higher sensitivity for detecting those subtle takes. Fluorocarbon is said to have less stretch than most nylon monofilaments, however there has been some debate among differing manufacturers.
Knotability
Knotability is often overlooked by anglers when selecting a leader or tippet material, but it is very important. The knot is always the weakest link in your setup and therefore it is important to choose a material that knots well.
Nylon monofilament is far superior here as it is suppler than fluorocarbon. For this reason, nylon monofilament is often the choice when tying big game leaders that require extremely large diameter lines. Due to the stiffness of fluorocarbon, knots do not always seat as easy and must be coaxed into lying just right. Take your time when tying knots into fluorocarbon materials and ensure the knot seats correctly to avoid knot slippage or breakage.
Summary
While fluorocarbon seems to have a great deal of advantages over tradition monofilament, there are certain situations where the extra cost is not necessary. Evaluate what situations best fit you and buy accordingly. Also, it is important to mention that not all materials are created equal. Fluorocarbon or monofilament is often times very different between competing manufacturers.
Mono. Far superior knot strength, especially with heavy steelhead leaders.
Great post that lays out the pros & cons. When making your own leaders, you can save by adding just a fluoro tippet but be sure the knot is strong. I like the double uni knot for this.
Mono. Hands down, at least for bonefish. As @Dan says (and you clearly point out) superior knot strength is the seller for me.
Also, mono is much more supple, where some flouro seems more like barbed wire than fishing line. It think this allows the fly to move more naturally in the water, which is what bones care most about.
Glad you brought up density. I fish mostly turtle grass flats, very shallow and dense. A flouro leader will drag a fly through the grass instead of over it, rendering the fly invisible to bonefish and snagging lots of grass. Mono floats slightly, allowing the fly to hop up out of the grass so the fish can see it, and then eat it.
Unless you’re fishing Hawaii and those volcanic-coral flats where you need abrasion resistance (and yes, I suppose casting to bones deep in the mangroves of the Bahamas), save the money on flouro and just buy the best mono you can find.
As always, great stuff here! Thanks.
Mono is a shortform of monofilament – right!
Both fluorocarbon, nylon and and nylon’s cocktails are monofilaments. All are produced by extrusion.
The term “monofilament” means a single filament as against say braided fishing line which is composed of many single fibres such as dyneema, braided together.
“Fluorocarbon” is the collective term for polymers in the fluorocarbon group, eg: PVDF (polyvynylidene fluoride, the stuff used in fishing leaders) and PTFE (polytetrafluoroethylene) which is used for coating non-stick frying pans for example.
“There’s more bullshit in fly fishing than in a Texas cattle yard”
While it is true that the refractive light index of Fluoro is closer to that of water than nylon (and hence virtually invisible to fish apparently) – this common misconception is in my opinion the single biggest load of garbage out there.
Having filmed and photographed fish, leaders and tippets for over 10 years (top side and underwater) I have never been able to see any appreciable difference between the two.
We’ve looked at tippet material in glasses of water, controlled aquariums and in fresh and saltwater at all sorts of depths and angles – It’s easily seen. My observations have been that both materials appear equally visible against a wide range of backgrounds. And I’m pretty certain my eyes and camera lens are not nearly as well adapted at seeing underwater as those of any fish I’ve observed.
In short, fish can see tippet, regardless of what material it is constructed from. My arbitrary observations aside, there have been a number scientific studies done on this. One such example is Jeff Thomson “Mathematical Theory of Fishing Line Visibility”
I have found that when Spey fishing for steelhead and using a trilene knot for the larger flys, the fluorocarbon tippet just breaks after a couple hours. My bet is on M*xim* monofilament. Good strength, good knotability, and more bang for the buck. I change tippet regularly and have never lost a fly due to just breaking off.
That being said, I have used a SA 5x fluorocarbon in place of a 4x mono for trout and have had good success and durability.
I would really like to know if heavier line, say 40 pond mono, is heavier than (sinks faster or slower) than 30 pound mono…
Harder the material the stronger the knot! …given the knot is seated right as you mentioned. Every knot that reaches its breaking point “pinches down”, and the diameter is reduced. Soft fly fishing mono tippet material pinches down more quickly than flouro.
I only have a few feet of Kroic Luxor left over from early 1980’s. Grey, non-flash (unlike fluorocarbon), great knot strength, and now unavailable anywhere. Shame.
Mono for me. Max Cam.
Have tried the fluoro in the past as a tippet material attached to a mono leader but had several issues with the knots slipping.
great informative article Thanks
You’re welcome Jim, glad you found it helpful!
Thanks Kyle…always a lot of opinions but flyfishing is about building context and this article really helps do that! If only I could remember it all next time I’m out fishing!
Love the article thank you!
I especially love the point about not clipping off chunks of fluorocarbon into the watershed.
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My team spent a good deal of time testing knots (tippet to fly)–because this was so relevant I wanted to add it here as a reference.
We tested the 7 most popular fishing knots on 4 different hook sizes using both fluorocarbon and monofilament.
Analyzing The Top 7 Fly Fishing Knots, Tippet To Fly [Clinch Ranked Last]