Fluorocarbon vs Monofilament Leaders/Tippet - What’s the Difference?

There is a fair amount of confusion when it comes to Fluorocarbon and Monofilament. Why are there two different materials, what is the difference between the two, and when/how does a fisherman decide to use them? There is definitely a difference between the two, and it's not just price. Most people think one of two things if they haven't compared them before, it's usually - they assume Fluoro is better because it's more expensive, OR they think it's a scam because "their grandfather caught a 60lb fish on mono and there's no need for fluoro." Both thought processes are indeed very reasonable. But, here are the main differences between Fluorocarbon and Monofilament and also, more importantly, when/how to use them.  

Strength/Durability

When it comes to comparing whether one material is "stronger" than another, there are a lot of factors to consider within leaders/tippet in fly fishing. Most of it however has to do with the manufacturer. If you look at a pack of leaders from Rio, their 3X tippet might have a different breaking strength listed than 3X from Scientific Anglers..Or one brand's 5X tippet seems wider than another brand's. This is just part of the deal- it can be confusing and present all kinds of variables. So with this article, I am going to be more concerned with what Mono or Fluoro is going to inherently provide for me. 

Fluorocarbon is significantly more durable than mono. There are a couple of reasons for this. For one, fluoro is a harder material than mono and provides a more abrasion resistant leader and tippet. This is important for situations when you're fishing nymphs along the bottom of a river, fishing on a coral flat for bonefish/permit, or swinging streamers for steelhead and salmon, or throwing deceivers off barnacle covered rocks for stripers.    

Fluorocarbon also does not absorb water or break down from the elements, including UV sun rays. Being impermeable to water, Fluoro does not weaken like mono after being continuously saturated. The fact that Fluorocarbon does not break down like Mono after a while is an important factor - especially if you are still reaching for that 4 year old spool of tippet in your sling pack...

Floating Or Sinking?

This is a consistent question I will ask myself when deciding what leader or tippet material to tie on. Monofilament is not as dense as Fluoro. This make mono more buoyant - quite a bit so actually...So, if I am about to throw some dry flies for trout, poppers for bass, or really anything on the surface I will grab the mono. On the other hand, anything sub-surface is better fished with fluorocarbon (think nymphs, streamers, wet flies). 

Visibility

This is a very hotly debated factor within this conversation. If you've heard one thing about the difference(s) of Fluoro vs Mono - this seems to be the one. Most likely because a product that is "more invisible" to fish seems to be pretty alluring. And although you can do a simple test with different strands of Fluoro and mono while dipping them in water on your own, I personally do not think there is a definitive difference, visibly, in water. As a human I can see a difference in the two while in water. But I'm a human with human eyes, not a fish with fish eyes. So I think the verdict is still out on this one...but certainly something to consider. 

Knots

As mentioned earlier, fluoro is more dense than mono. This makes mono better for tying knots as the softness of mono provides better grip for the knot. Although I have not personally seen a distinct failed knot due to fluoro, I do see a very clear difference when tying knots especially in heavier tippets. If I'm making leaders for larger species like tarpon, I find mono much easier to work with.

The Winner...?

Is there one? Not sure...I think it's really more situationally based than anything else. Monofiliament and Fluorocarbon are certainly different and can be individually advantageous if used properly. Fluorocarbon, although more expensive, can give the angler a better material for certain tactics - on the other hand you can be out-fished by another guy fishing mono if it's the right situation. 

Words + Photo: Josh Thelin