Mono stretches and forgives. Braid does not stretch and transmits everything. Fluorocarbon is nearly invisible, stiff and sinks — which makes it a leader.
What each one is
Monofilament is a single nylon strand. It stretches, which is forgiveness on a hook-set and vagueness on a bite, and it holds the coil of the spool — what the trade calls memory. It resists abrasion better than braid.
Braid is several polyethylene fibres woven together, and the corpus states the count in almost every title: 4-fach, X8, 8-fach. It does not stretch, so a bite at forty metres arrives at the rod tip unchanged.
Fluorocarbon has a refractive index close to water’s, so it is far less visible at the same diameter. It is also stiffer and sinks.
How they are usually combined
The common arrangement is braid on the reel and a fluorocarbon or nylon leader at the end — braid for the sensitivity and the casting distance, the leader for the invisibility and the abrasion.
Two cautions from the corpus. A leader marked « 100% » is solid fluorocarbon; one marked « Fluorocarbon Coated » is a nylon with a skin and behaves like nylon. And neither of them is bite-proof: a pike cuts both, which is the entire reason the wire trace shelf exists.
Where this page disagrees with the maker’s own documentation, the documentation wins. Every length, casting weight, test curve, line diameter, breaking strain, reel size, retrieve per turn, drag force, buoyancy rating, mesh size and mass on this page is the maker’s own published figure, in the unit as printed, credited to whoever printed it. Nothing here is measured, and no figure is restated in another convention — a pound test curve is not turned into grams, and a kilogram of breaking strain is not turned into pounds, because a converted number is a different number. And the pair this page will not separate: a diameter and a breaking strain are one figure in two halves. Two lines at 0,18 mm can break at different loads, and two lines at the same load can be different diameters — which is the whole of the choice. A listing that publishes one of the two has published half a specification, and this page says which half is missing rather than filling it in.
The questions that keep coming back
Why does braid need a leader?
Because it has no stretch and no forgiveness, and it is visible in water whatever its colour. A nylon or fluorocarbon leader adds both back at the business end.
Is braid really that much thinner?
The corpus prints 0,13 mm at 8,0 kg on a braid and 0,45 mm at 18 kg on a nylon. A nylon at 0,13 mm breaks around 2 kg, so yes — at equal strength braid is a fraction of the diameter.
Can fluorocarbon be a main line?
It is stiffer than nylon and it sinks, which makes it awkward on a reel and useful as a leader. The corpus sells it in 30 m and 50 m lengths and as ready-made leaders, which tells you how it is actually used.
Last reviewed 22 September 2026