Fluorocarbon vs Monofilament and the Surprising Truth

Over the years, fluorocarbon fishing line has gained popularity among anglers of all types. But why? Is fluoro better than mono? Even more so, what’s the difference when it comes to fluorocarbon vs monofilament fishing lines? Instead of deciding which is better for your unique situation, I’ll break it down by concepts.

What’s the Difference Between Fluorocarbon and Monofilament?

As similar as they look and even feel, fluorocarbon and mono are actually quite different. The most commonly known discrepancy is the visibility under water. Additionally, fluorocarbon sinks while mono floats (with few exceptions). The difference in memory and stretch also vary, but typically, fluoro has more memory. Another common reason anglers might choose to use fluorocarbon for a leader is because of its supposed better abrasion resistance.

Is Fluorocarbon Invisible Underwater?

This is the big one. The main reason fluorocarbon has become so popular in the fishing world is because it’s said to be virtually invisible underwater. So is fluorocarbon invisible? The straight answer… no, it’s not invisible, but it is less visible than any other type of fishing line.

Line-visibility is determined by refraction indeces (indexes) and the goal is to come as close as possible to the same refraction index of water itself. It’s important to note that refraction indeces can vary depending on a multitude of factors including temperature and salinity. With that in mind, here are the numbers (corresponding average refraction indeces):

• Fresh Water: 1.33
• Salt Water: 1.35
• Fluoro: 1.42
• Mono: 1.55
• Air (for reference): 1.0003

What the heck do those number mean, huh? Well, light actually bends when it passes through objects/things, and things with higher indeces (from 1), cause the light to bend more. Whether you understand it or not, the idea is to create a fishing line with a refraction index as close to that of water’s. And, in our case, it’s a little easier because salt water (1.35) has a higher refraction index than fresh water (1.33).

So, you can see that in terms of fluorocarbon vs monofilament, fluorocarbon is only .07 away from the refraction index of saltwater and .09 away from freshwater. On the other hand, monofilament is .20 and .22 away (respectively).

If you’re a big believer in fish being line shy, than fluorocarbon is a must-have for you. If not, it really can’t hurt so it’s still a solid option.

Fluorocarbon vs Monofilament: Does Fluorocarbon Sink??

Yes, fluorocarbon does sink as it’s engineering causes it to be denser than monofilament. For this reason, it’s a popular choice for deep trolling, bottom fishing and any other style of fishing that might benefit from a quick-sinking bait or lure. There isn’t much more to that topic, but yes, fluorocarbon line will sink while mono will float (on it’s own).

Does Fluoro Cast Farther Than Mono?

If you’re looking to gain a little extra distance on your cast, I’d look beyond this question. If I had to guess, mono casts a little further because it’s less rigid in nature. But, braid will cast further than both of them. Additionally, a quality rod with smaller and more guides along with a high quality reel with a good spool will play more into casting distance than weighing the difference between mono and fluoro. Heck, practicing your casting technique is probably step one if you’re looking to gain some extra distance.

Fluorocarbon Coated vs 100% Fluorocarbon

This was a question I came across when I was just starting to use fluorocarbon and there’s a very simple answer.

If you search for fluorocarbon, there’s a chance you’ll come across fluorocarbon coated monofilaments. I would steer clear of any sort of “fluoro-coated” lines. Seaguar (the brand that invented fluorocarbon) puts it like this, “you can paint a red car with a clear coat, but you’ll still see the red through it”. Granted, fluoro isn’t truly a perfect “clear coat”, but the analogy is still relevant.

An argument could be made that fluorocarbon coated lines have better abrasion resistance than classic nylon monofilaments. But, there have been many tests suggesting fluoro is no more abrasion resistant than mono. In fact, I’ve seen a myriad of tests that give the edge to monofilament.

Fluorocarbon Leader Line vs Main Line

Possibly the most shocking find in doing my homework on this subject was the overwhelming consensus that fluorocarbon “leader line” might be no more abrasion resistant than fluorocarbon “main line”. For the longest time, I wondered what the difference was and why some fluorocarbon costed upwards of $0.50 per yard (leader line) while others costed less than $0.10 per yard (main line).

After watching multiple abrasion tests, there was no real difference found in abrasion resistance. Additionally, since all fluorocarbon (100% fluoro) has the same refraction index, whether you buy expensive leader line or fluoro main line, it’s all the same in terms of refraction.

That concept right there could be a real money-saver for a lot of you. I’ve used Seaguar Red Label (which is a main-line fluorocarbon line) as my leader line for as long as I can remember and it’s worked just fine for me. Seaguar and many other fluorocarbon brands offer salt water specific lines, but after doing my research, I’m convinced that it isn’t necessary. If you’re curious, here’s my exact surf fishing set-up with detailed explanations of why I use what I use. The main point here is that even if you’re just using fluorocarbon as a leader, you don’t need to spend loads of money to get the leader-specific types of fluorocarbon, just get the normal (main-line type) fluorocarbon… as long as it’s 100% fluorocarbon.

Features of Fluorocarbon vs Monofilament

• Less stretch than mono but still some stretch
• Less visible (closest refraction index to that of water)
• Sinks rather than floats
• Longer lasting/ less prone to sun damage
• Higher sensitivity than mono