Most carp anglers use 12 to 15 lb monofilament as mainline. It's cheap, stretchy and forgiving, and almost every fishery allows it. Fluorocarbon sinks and hides better at a higher price. Use braid only where the fishery allows it, and only for distance work, spodding or marker rods.
What the mainline does
The mainline runs from your reel to your lead and rig. It takes the strain of casting, playing fish and pulling free of weed, so it has to be strong, tough and reliable. It's also the part of your tackle carp are most likely to touch as they swim through the swim.
There are three types: monofilament (mono), braid and fluorocarbon. Each one behaves differently.
Mono, braid or fluorocarbon
| Mono | Fluorocarbon | Braid | |
|---|---|---|---|
| Stretch | Lots, which cushions the fight | Some | Almost none |
| Sinks? | Slowly | Yes, lies flat on the bottom | Most float |
| Visibility | Moderate | Low | High |
| Abrasion resistance | Good | Very good | Poor on sharp edges |
| Casting distance | Good | Good | Best |
| Cost | Low | High | Medium to high |
| Allowed as mainline? | Almost everywhere | Almost everywhere | Often banned |
| Best for | Everyday fishing, beginners | Pressured or clear waters | Spod and marker rods, distance |
Mono
Mono is the default choice, and for good reason. It's cheap, easy to tie knots in, and its stretch acts as a shock absorber when a carp lunges near the net, which means fewer hook pulls. It sinks slowly, so back-lead or sink it properly.
Fluorocarbon
Fluorocarbon is denser than water, so it sinks quickly and lies flat on the lake bed, out of the way of fish. It's also harder to see. On busy, clear or heavily pressured lakes, those things can make a difference. It costs more, and some types are stiff and need care when tying knots.
Braid
Braid is thin and has almost no stretch, so it casts a long way and shows every knock on the lead. That's why it's used on spod rods and marker rods. As a mainline for playing carp it has real drawbacks: it can cut fish and other lines, and the lack of stretch leads to hook pulls.
Many fisheries ban braid as a mainline for fish safety. Some allow it for spod and marker rods only. Check the rules before you spool up.
Which breaking strain
- 12 lb mono for open water with few snags.
- 15 lb mono as an all-rounder, and around weed or light snags.
- 15 to 18 lb mono for heavy weed and snags, where you need to stop fish quickly.
- A shock leader of around 50 to 60 lb for casting heavy leads hard. It protects your mainline from snapping at the moment of casting.
Whatever the breaking strain, the line and the rest of your set-up must be balanced. A very heavy line on a soft rod doesn't make you any stronger, it just makes the weakest link somewhere else.
How to spool a reel
Items required: the reel, the line, a pencil or spooling station, and a bowl of water.
- Put the line spool in a bowl of water or on a spooling station so it turns freely.
- Open the bail arm, tie the line onto the spool with an arbor knot, and close the bail arm.
- Wind on slowly, holding the line between finger and thumb to keep it under light tension.
- Stop when the line is about 2 mm below the spool lip. Overfilling causes tangles; underfilling cuts casting distance.
- Fill every reel you'll use the same way, so each one casts the same.
Mark the line at your fishing distance with a pole elastic stop knot or a line marker, so you can hit the same spot every cast. The spodding guide explains clipping up.
Looking after your line
Mono weakens over time, especially in sunlight. Run the last few metres through your fingers before each session. If it feels rough, kinked or dull, cut it back. Replace the whole line at least once a season, and sooner if you fish a lot.
For what goes on the end of the mainline, see lead clip, helicopter or inline, and for the knots, carp knots.
Questions
What breaking strain mainline do I need for carp?
12 to 15 lb mono suits most lakes. Go up to 15 to 18 lb around snags or weed, and use a shock leader of around 50 to 60 lb when casting heavy leads hard.
Why do some fisheries ban braid?
Braid has almost no stretch and cuts easily through soft tissue, so a fish can be injured if the line rubs across it. It can also cut through other anglers' lines. Many fisheries ban braid as mainline, though they may allow it for spod and marker rods.
How often should I change my mainline?
Check it often, and replace it at least once a season, or sooner if it looks dull, kinked or nicked. Mono weakens with UV light and wear, and the last few metres take most of the abuse.
Is fluorocarbon worth the money?
It's denser than water, so it sinks and lies flat on the bottom, and it's less visible. That helps on pressured waters. For a first set-up, good mono does the job at a fraction of the cost.
How much line do I need on my reel?
Fill the spool to within about 2 mm of the lip. Most carp reels hold 200 to 300 m of 12 to 15 lb mono, which is plenty for nearly any lake.
