Everything you wanted to know about mainlines

Everything you wanted to know about mainlines
 Mainlines are our direct connection to the underwater world

Mainlines are our direct connection to the underwater world

The sheer variety of carp mainlines on the market can be a confusing affair for consumers.

It’s not as simple as just choosing a type of line – say, monofilament or braid. It’s the subtle differences between individual products that seem to cause the most consternation.

Here at Gardner, we regularly receive enquiries from anglers wanting to know ‘which line is best, and why?’ Some of these guys come across as experienced and knowledgeable types seeking a heads up on the ‘best of the best’ or ways to maximise the performance of a product.

Others don’t seem to get the complexities involved in ‘rating’ a line, or the nuances in terms of feel and performance between different types.

Obviously an area where some helpful info wouldn’t go amiss, so here goes…

Line basics

Let’s start with the basic premise that you have a set of reels and each has been supplied with a spare spool. How do you decide what goes on each?

Well, I would say that most UK angling is covered by the two main types of monofilament – either copolymer or fluorocarbon.

These are both extruded products, which start as a molten mixture that is pushed through a die and then stretched out in a controlled manner (causing the molecules to align, giving the finished line its strength), but that manufacturing process is where the properties of each line differ in terms of the final user experience.


Copolymers are, broadly speaking, amazing all-round performers. Their weight (density) allows them to both sink and flow effortlessly from the reel, funneling smoothly into the butt eye during casting.

 Gardner is known for its quality range of lines

Gardner is known for its quality range of lines

They are generally easy to knot, durable, and come in a variety of colours, breaking strains and diameters. The manufacturers can adjust particular attributes to make individual blends suit specific angling purposes too.

If you change one key characteristic on a copolymer it normally (subtly) impacts upon at least one other.

For instance, say we want a high abrasion/robust line. I know that on the whole they are based on a slightly firmer copolymer blend that is also a little opaque (white) in its natural form.

This ‘firmer’ blend means you get exceptional knot strength and an extremely robust line, but the trade-off is that when compared to a really soft ‘casting line’ you may notice it’s a tiny bit stiffer.

However, differences like this are almost negligible unless you’re comparing like with like.

If you want a great copolymer that offers all-round ease of use, including knotting and great ‘wear and tear’, then this opens up a wider array of blends that will be marginally less robust – but will be smoother casting and maintain minimal stretch for feeling leads down.

The base colour of these materials is naturally clearer, and that means that there is wider scope for the addition of lower levels of pigment, which in turn means you can get some really nice ‘low-viz’ lines.

Realistically, if you’re ‘big-fish’ angling, strength and reliability should be your number-one concern, especially if there are gravel bars present, as well as significant weed beds and marginal snags to contend with.

The raw strength relates directly to the line’s diameter, and how it performs when knotted, and the rating on the spool should be looked at as an indicator of the minimum breaking strain you should expect with a recommended knot.

If in doubt, look at a manufacturer’s website – like ours for instance!

Some lines certainly do need a specific knot to optimise strength, and generic test tables sometimes don’t take this into account as they should.

For instance, GT-HD certainly offers more consistent strength with a Palomar knot, and if you add an extra half twist into either the figure-of-eight knot or Palomar, you can get an extra 10 per cent on top of that!

That means the 0.39mm version can attain over 27lb! Most all-round copolymers offer high relative knot strength with either a Palomar or a grinner knot, and anglers should be able to tie both effectively.

One or the other will do the job, offering around 90 per cent of the line’s linear strength when tied properly.

When fishing for proper big fish, I don’t think you should drop below 0.35mm line unless you need to fish long, and also have a boat to help you land fish from the bank.

Ideally, as the weed comes up or when the lake is particularly challenging in terms of topographical features, you may consider moving up to a 0.38mm or 0.40mm mainline and also fishing in a safer manner (essentially that means at closer range, where you will have greater control over any hooked carp).

Why? Well, with increases in diameter you gain marked increases in strength (both linear and knot), sheer resistance and general ‘ruggedness’ AND its relative speed of sinking – but your casting range will be inhibited.

In terms of fish safety, if the conditions are so difficult that you need to upscale your gear to minimise tackle failure, then the last thing you want to be doing is casting a mile out into the pond and making it even harder to land all the fish you hook. That’s common sense, isn’t it?

Fabulous fluoros

So, what about the other type of monofilament, namely fluorocarbon?

 Lewis has come to love fluorocarbons

Lewis has come to love fluorocarbons

Well, the more I fish with this stuff, the more I feel that it is an absolute necessity! I’m utterly certain that it gets me more bites – and I suspect this is largely as a consequence of it working on a ‘tip-to-rig’ line concealment principle.

Hence, I would suggest that you really consider putting a pure fluorocarbon, like Mirage, on your spare spool.

It’s expensive stuff, but consider it an investment. It generally has a longer lifespan than copolymers as it is hydrophobic and isn’t affected by exposure to UV light.

Fluorocarbon could be classed as the ‘Marmite’ of fishing lines! Some anglers seem to hate the stuff as they (unrealistically) expect it to act and feel like a copolymer - but it never will!

There’s no arguing it’s quirky, and you need to tailor your knots to get the best from it, but I fully believe that it is in a league of its own in terms of concealing your presence.

I could restate the well-worn facts about its amazing transparency and the fact it has the same refractive index as water – but I don’t personally believe these characteristics have much to do with its effectiveness.

It’s simply its density and the fact that it sits much lower than conventional lines that means the fish don’t notice it! It’s definitely my number-one choice for close or medium-range fishing.

Why’s it quirky? Well, it’s so heavy it tends to overrun (frap) on standard butt rings, and the most consistent knot is a tucked blood!

This knot is so goddamn awful with any other line that it should come with a warning, but it works really well with the fluorocarbon as the material’s density stops it from constricting (the same characteristic that makes it much better than copolymers for use with naked chod rigs).

Braided mainlines

The final line type of mainlines to rattle on about are braided ones. These are highly specialised products that are broadly manufactured and sold as either neutral buoyancy or sinking lines.

 Braided mainlines scare many off, but they have their place

Braided mainlines scare many off, but they have their place

Neutral-buoyancy braided mainlines (like our Kinetic range) are manufactured from pure Dyneema fibres. The final pure product has a low diameter in relation to its breaking strain, and is mainly used as a ‘leading’ or ‘feature-finding’ tool by specialists.

Its near-zero stretch allows you to feel infinitely more detail as you pull a lead across the lakebed.

Many commercial fisheries do not allow braided mainlines, but it is allowed on some big waters here in the UK because the anglers that approach these venues are expected to be experienced enough to use it safely.

It’s arguable that it could potentially be a little severe on a fish’s mouth when compared to monofilaments, but in reality I suspect that is mainly down to opinion, rather than fact. After all, as anglers we know how much pressure we’re applying, and most reels have excellent clutches.

What’s more, braided mainlines are standard fare on the Continent.

Closely related to these are sinking braided mainlines, which are similarly constructed, but also include a portion of fibres that increase the specific gravity of the final blend so that it’s heavier than water.

In the case of our Hydro-Sink braided mainline we use Kevlar fibres to achieve this, but other companies may incorporate fluorocarbon fibres or even plain old polyester to achieve the same or a similar effect.

If you’re using a pure Dyneema mainline then specialist knots like the Bimini Twist offer enormously stronger knot strength when compared to a relatively poor-performing grinner or Palomar.

The benefits of tailoring your knots to a braided mainline cannot be overstated – it’s essential that you look to achieve the highest possible performance from any line by tailoring your knots to suit the product (not the other way around).

Having a wide variety of lines to choose from may be a little confusing at first, but essentially having choice means you should be able to find a line that you get on with and have utter confidence in.

And, as with most other things related to the key pieces of tackle you rely on, when you have found something you like, stick with it!