In 1966, chemists at Kureha Chemical Corporation of Japan realized that fluorocarbon's resistance to heat, light, and chemicals offered advantages in fishing line. They found it unaffected by UV rays that weaken mono, a characteristic that aids its longevity, and filed a patent for fluorocarbon fishing line.
Nearly 15 years ago, spoolable fluorocarbons burst onto the freshwater scene, led by pioneers including Stren Fluorocarbon, Berkley Vanish, and Seaguar Carbon Pro. While saltwater anglers were familiar with fluoro — having used the stiff yet tough and nearly invisible line as leader material for some time — it didn't find favor inland until offerings supple enough to spool were introduced.
Today, options in fluorocarbon line have grown exponentially, while advances in castability have made it more user friendly, though still stiffer than monofilament. For a look at some situations where it shines, we check in with two avid Midwestern anglers.
Scott Glorvigen of Grand Rapids, Minnesota, a veteran guide and tournament competitor, notes the product's steady improvement since the early days, when slinky-like coils sprang from the spool, it broke inconsistently, and applying extreme pressure — typically when trying to free a snagged lure — changed its properties.
"Fluorocarbon gets better every season," he says. But, while he believes manageability is approaching that of mono, he seldom spools entirely with fluoro, or endorses its full-scale use for broad applications — such as walleye rigging or jigging. Rather, he judiciously applies the line's unique properties to specific fishing situations.
"I use it as a specialty tool, often for tough bites or other challenging conditions, especially in clear water," Glorvigen says. He adds that the benefits of fluorocarbon's thin diameter rank with its low-vis features when choosing fluoro or mono. "I rely on fluorocarbon during a tough bite related to a major cold front," he says. "A slow presentation, such as pulling a nightcrawler on a slipsinker rig, can save the day. Downsizing everything — including line diameter — helps you catch more fish. It's thinner than mono, and thinner line is harder for fish to detect with their lateral lines. During a tough bite, little details like this can make a big difference."
His typical rig includes a 36-inch or shorter section of 4- to 6-pound fluoro, linked to a low-stretch monofilament mainline by a #10 to #12 barrel swivel. He goes with #8 or #10 thin-wire hooks, lightly nose-hooks the 'crawler and injects just enough air to suspend it above bottom, when tethered to a 1/16- to 1/8-ounce egg sinker. "Dragging on bottom creates resistance for a fish when it takes the bait," he says. "Make sure the entire rig hovers near bottom, but don't drag the sinker."
Best-known for his walleye exploits — including an In-Fisherman Professional Walleye Trail Championship win — Glorvigen is an accomplished multispecies angler and finds applications for fluorocarbon there as well. "Fluorocarbon leaders are great for float-fishing crappies near the surface in clear water," he says. "I tie a little ice-fishing jig, such as a Northland Bro Bug or Slug Bug, on a loop knot to a 2- to 3-foot leader of 2-pound fluoro. Downsizing line diameter reduces water displacement and gives the fish less ability to feel it." Thin line also moves through the water more easily when a finicky crappie flares its gills to inhale the jig.
Glorvigen also favors fluoro when drift-fishing steelhead in gin-clear streams. "Steelhead are highly aware of their surroundings. When I'm perpendicular to the river, casting out and letting the current take the bait downstream, they can feel the line coming toward them," he says. "Fluorocarbon is not only harder for fish to see, its thin diameter is more difficult to feel. It also has a tendency to keep baits close to bottom, thanks to its sinking properties."
For steelies, he spools fluoro on a center-pin fly reel. Its large arbor limits twist and memory, and he appreciates the line's extra sensitivity. "With my finger on the line, I can feel the bait stop much better than with mono," he says. "Fluorocarbon also repels water, so it resists ice buildup in cold conditions."
On the bass scene, fluoros have found favor in many quarters. Some touring pros use it for up to 70 percent of their tactics, especially when plying deep water with crankbaits or Carolina rigs, because it trumps mono in sensitivity and is less visible than braid. When cranking, fluorocarbon's thin diameter boosts running depth over mono.
Other pros embrace the product, but prefer to pigeonhole it for specific duties. Minnesota bass ace Scott Bonnema falls into the latter camp. Like Glorvigen, he picks and chooses, playing the fluoro card only when the time is right.
"One of its benefits is that it virtually disappears under water — so it helps fool fish because they can't see the line ahead of the lure," he notes. "Moreover, it's more sensitive than mono, so you can detect subtle bites. Another benefit is its thin diameter, which allows you to increase pound-test to reduce the potential for break-offs."
That said, he largely reserves it for duty as leader material, pairing it with braid when jigworming, drop-shotting, and many other presentations. "Except when fishing dense vegetation with a jig or weedless frog, I use a fluorocarbon leader with braid attached with a double uni-knot."
He uses fluoro as a mainline when pitching soft-plastics such as Trigger X Flappin' Craws, favoring 14- to 17-pound Sufix Castable Invisiline 100% Fluorocarbon. "It pitches smoothly, offers good sensitivity, and I don't have to retie leaders when frequently switching baits," he explains.
Bonnema also spools fluoro when dragging tubes on spinning gear and when fishing multi-task softbaits like the Trigger X Slop Hopper, which shines as a topwater slop bait and also as an open-water swimbait. "I'm confident casting and pitching these baits with fluorocarbon, because I know it produces more bites," he says, "though I don't to use it in the heaviest cover."
For their diameter, most fluorocarbons are abrasion-resistant, but it's wise to frequently check for line-weakening nicks, especially when fishing rough neighborhoods, such as bottoms coated in zebra mussels, where thin lines and drop-shot rigs reign. And the final 6 inches of line tends to wear under the stress of repeated casting and dragging.
While debates have raged about fluorocarbon's ability to hold a knot, Bonnema hasn't had problems. "Take time to properly tie a Palomar or improved clinch — wetting the line before cinching it down tightly — and you shouldn't have problems," he says.
Forget fluorocarbon for throwing topwater lures because it sinks. While some pros spool fluoro for cranking, feeling it increases running depth, Bonnema cautions that its density can stymie the effectiveness of jerkbaits or crankbaits fished in a stop-and-go manner. He's found that it pulls baits downward when paused instead of sitting still, which can be important to drawing strikes in cold water and at other times as well. He also feels mono increases casting distance.
Today's fluorocarbons offer benefits and trade-offs, making it an ideal choice in some situations and thus worth the extra cost, but less than ideal in others. Be aware of the formulations available, as they differ considerably in their characteristics. Success stems from trying top-end brands for your personal style of fishing, and keeping an open mind as you discover new ways to wield this relatively new and steadily evolving fishing tool.
Berkley Trilene 100% Fluorocarbon XL
- Featuring a formula that makes it limp enough for spinning gear, this new fluoro is ideal for drop-shotting and shaky-head applications. Available in 200-yard spools, in 4- through 12-pound tests.
Hi-Seas Grand Slam Fluorocarbon
- A copolymer cloaked in fluorocarbon coating, this new product offers low visibility, durability, and manageability — plus it casts well. Available in 300-yard filler spools from 4- to 20-pound test.
- Unveiled in 2012, this multi-faceted fluoro features double-structure construction, with a soft exterior to enhance knot strength, plus high-density inner resins that boost tensile strength. Available in 4- to 25-pound tests on 200-yard spools.
Sufix Castable Invisiline 100% Fluorocarbon
- Pure fluorocarbon, Invisiline is spun with an exclusive G2 Precision Winding process that all but erases memory. It handles well on spinning and casting gear, is abrasion-resistant, and sinks four times faster than mono. Available in 3- to 20-pound tests.
Sunline Structure FC Fluorocarbon
- New this summer, Structure FC was developed with the aid of veteran bass pro Mike McClelland. It's a low-stretch, abrasion-resistant line that shines when fishing football-head jigs and umbrella rigs around structure and for Carolina rigging. Available in 165-yard spools, in 14- to 25-pound tests.