Barbel are a hard fighting fish that have a liking for snaggy swims. This means that tackle must be strong enough to land the fish you are after. The line strength and type that you choose will depend on the size of fish concerned, and the nature of the river being fished. There are other concerns to be considered too.

Mono
If fishing for small barbel in swims free of snags then lighter tackle can be used than if you are after large fish in rocky swims. In clear situations with plenty of room to play fish even large barbel can be safely fished for with eight or ten pound nylon monofilament lines provided a rod balanced to those lines is used. It is folly to use light lines with powerful rods or heavy leads.

In snaggier situations, or on rivers noted for their rocky beds like the Wye and Ribble, it is wise to use mono of 12lb or stronger. The same applies when fishing wide rivers like the Trent or Thames with heavy feeders. At times this may require the casting of weights in excess of six ounces, and a fifteen pound mono is a much safer proposition in this case.

As with hooks the particular brand of line you choose is a personal thing. For some reason two anglers can have completely opposing views and experiences of the same line. One thing is for sure when it comes to mono, cheap lines can be as good and as reliable as expensive ones.

It is always worth checking the diameters of monofilaments and when comparing different brands this is more important a comparison point than breaking strain. You may be surprised at how these can vary from one line to another. As a rough guide the table below gives a rough guide to the diameters of basic nylon monofilaments you can expect for a range of breaking strains suitable for barbel fishing.

8lb	0.280 mm	0.0110 in
10lb	0.300 mm	0.0135 in
12lb	0.325 mm	0.0147 in
15lb	0.350 mm	0.0158 in

It is always best to use the strongest line you can which doesn't adversely affect your bait presentation. Which brings us to braided lines.

Fluorocarbon
Mention flurocarbon lines to a group of barbel anglers and you will get reactions ranging from outright loathing to pure delight. Not only that but each brand seems to elicit a different response. The main advantage of flurocarbon lines is that it matches the refractive index of water - in layman's terms this means it is almost invisible underwater. However, it is stiffer than nylon, and can be less tolerant of poorly tied knots. As a hooklink it obviously be beneficial to presentation in clear water during daylight. Some also say that it's surface feel is less scary to spooky fish.

As a mainline its reduced stretch and reputed improved abrasion resistance may be benefits or not. It's price certainly isn't. There are, though, lines which have an inner core of nylon and an outer coating of flurocarbon. These are supposed to combine benefits of both line types. Although a coating of flurocarbon will not render the line completely invisible it should appear thinner than a nylon line of the same overall thickness. Again, some anglers love these hybrid lines, others detest them.

Read an interesting comparison of flurocarbon lines here.

Braid
There are many misconceptions held about braided lines, mostly by those who have never used them. The first is that they are too strong, and there is 'no need for such breaking strains". A common statement is that "you can catch sharks on 30lb line". Well, yes you can on 30lb mono, but 30lb braid is a different beast. It is like comparing apples and oranges.

Because braid (strictly speaking Spectra or Dyneema braid) has almost no stretch this means that it lacks the shock absorbency that is inherent in nylon. As a result a stronger line has to be used to compensate for this. Braids also have different tolerances to being knotted compared to nylon. This is most noticeable in finer braids where knotting can be markedly reduce the line's breaking strain. Despite the fact that braids lose a higher percentage of their breaking strain when knotted than do nylons, braids retain their knot strength far better than do monos. Knots in nylon should be cut and retied at the start of every session if you are an angler who leaves their rods made up. Braid, on the other hand, can be left, literally, for months on end.

The same applies to the lines themselves. Spectra and Dyneema do not degrade at anything like the rate that mono does. You can safely use braid that is five or more years old, whereas a nylon of that age could not be trusted.

Given the above the usual recommendation for selecting a braided line for the first time is to choose one that has a similar, or slightly smaller, diameter to the nylon mono you currently use. In practice this might mean switching from a twelve pound nylon to a thirty pound braid. Different braids have their breaking strains quoted in different ways. This means that one 30lb braid might appear to be much thinner than another. Ignore this and buy on diameter as it is likely that the thinner line will have its unknotted breaking strain listed, while the thicker one will have its knotted strength printed on the spool.

It is often recommended that for fishing rocky rivers mono is the best choice as nylon is supposedly more abrasion resistant than braid. There is a degree of truth in this, if you are comparing mono and braid of the same breaking strain. But bear in mind that this is not a fair comparison. If you were to do a similar test between monos of such varying diameter you would expect the thinner one to withstand less abrasion than the thicker one. In practice braid of a similar diameter to fifteen pound nylon will be perfectly adequate for use in rocky conditions.

It is also sometimes said that damage to nylon is more noticeable than damage to braid as nylon feels roughed up. However, braid shows signs of wear by taking on a 'furry' appearance.

The biggest advantages braids have to offer barbel anglers are increased sensitivity - more so when using tactile methods such as touch legering, and increased strength that enables you to free snagged tackle more easily than you can with nylon.