Rig guides · part of the rig library

What line should I use?

Mono, fluorocarbon and braid: what each one is, how it behaves, and the ruler that pairs a diameter with a breaking strain.

Part of the rig library: the rig specs carry the recommendation for a given rig, this page carries the facts.

The three lines

Monofilament Fluorocarbon Braid
What it is Single strand of nylon. The general-purpose line A denser, stiffer polymer with a refractive index close to water Woven strands of polyethylene fibre. Very thin for its strength
Stretch Stretches 15-25%, which cushions a hook-pull and a lunge on light hooklengths Less than mono, so it transmits bites and hits harder on the strike Almost none. Every tap at the feeder shows on the tip
Visibility Refracts light. Fine diameters are hard for a fish to see; heavy mono in clear water is not Near invisible in clear water. The reason it exists Opaque. Always paired with a mono or fluorocarbon hooklength
Float or sink Slightly buoyant. Floats until it is sunk, which a waggler angler wants and a feeder angler does not Sinks fast. A fluorocarbon hooklength lies flat on the deck and a fluorocarbon mainline cuts through surface drift Floats unless it is a sinking braid. Add a shockleader for casting heavy feeders
Abrasion Fair. Nicks easily on gravel and snags; check the last metre often Best of the three. Stands up to gravel bars, mussels and carp scales Poor on sharp edges despite the strength rating. Frays on gravel; a damaged section goes with no warning
Knots Ties easily and holds well. Wet the knot before pulling tight Stiff and slippery: use a grinner or Palomar and wet it. A badly tied fluorocarbon knot fails without warning Slips on plain knots. Use a Palomar or double grinner, and a leader knot to mono
Where it goes Mainline on pole and waggler rigs. Hooklengths for most float and pole work. Fly leaders and tippet Hooklengths on feeder, bomb and pellet-waggler rigs. Stiff boom sections and hooklengths on carp rigs. Winter silvers hooklengths in clear water where the extra stiffness also keeps a fine line from tangling Feeder mainline at range on lakes and rivers, and sea mainline. Never as a hooklength on match rigs, and check the rules: some fisheries ban it

Diameters and breaking strains

Diameter Typical breaking strain Where it goes
0.08 mm 1.0-1.5 lb Canal silvers hooklengths
0.10 mm 1.5-2.0 lb Silvers hooklengths, winter
0.12 mm 2.5-3.0 lb Silvers mainline, F1 hooklengths
0.13 mm 3.0-3.5 lb Hooklengths under 0.16 mainline
0.15 mm 4.0-4.5 lb F1 and small carp hooklengths
0.17 mm 5.0-6.0 lb Commercial carp hooklengths, margin mainline
0.19 mm 6.5-7.0 lb Margin and shallow pole mainline
0.22 mm 8-10 lb Feeder and bomb mainline, big-fish margins
0.26 mm 12 lb Straight lead hooklengths for big carp

Diameter to breaking strain is brand dependent; these are the rounded figures most match lines print on the spool.

Rules of thumb

  • Hooklength always lighter than the mainline, by about 0.03 mm on the pole. If something has to go, it is the hook, not the float.
  • Match the line to the hook: a fine-wire size 20 on 0.08 mm, a size 12 on 0.17 mm and up. A heavy hook on a light line breaks the line; a light hook on a heavy line opens out.
  • Stretch is a cushion. Braid to a light mono hooklength needs a soft tip or a softer hook; mono straight through forgives a lot more.
  • Line ages. Sunlight, heat and a season of casting knock the rating down. Respool a feeder reel every season and re-tie pole rigs that have been in the wallet a year.

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