4 types of fly line and when to use them

4 types of fly line and when to use them

Before you match the hatch, you need to match your fly line to the tactics you have in mind… 

Their pretty colours aside (and we’ll get back to that later) fly lines can look much of a muchness when they’re all lined up in their boxes and bags in your local tackle shop.

Get closer to them, though, note the hieroglyphics of hashtags, numbers and ‘WF’s on their packaging and you quickly realise not all lines are the same.

Here’s what you need to know before picking one that’s right for you…

WF floating line

This is widely seen as the best choice for the novice. ‘WF’ means ‘weight-forward’ –most of the line’s weight is found at the line’s front end, helping the rod bend or ‘flex’ during false casting which in turn helps you cast further when you shoot the line towards its target. 

Recommended if …

  • You’re fishing shallow water. Take an intermediate line (see below) with you as well and you’ve covered all the bases.
  • You’re fishing flies on or in the surface film.
  • You’re struggling to tell if you’ve had a bite. Any unusual movement in the line floating on the surface will often be a visual confirmation.
  • You’re fishing big flies. The front-loaded line turns over more readily, helping the fly land more naturally on the water. 

Intermediate line

This is a sinking line (see below) but one that takes its time, allowing you to fish at various depths. How slow is the sink rate varies from line to line, so check the packaging (or ask your retailer) for details. Some makes can be hard to sink at all when new; help them along by adding a slow-sinking braided loop.

Most intermediate lines don’t sink so far and then stop: you must retrieve to keep the line at the depth you need.  

Recommended if…:

  • You’re ‘prospecting’; fishing different depths to find how deep the fish are.
  • Strong wind is playing havoc with any line floating on the surface. Keep the intermediate line entirely out of the breeze by submerging your rod tip when retrieving.
  • You’re fishing the zone just below the surface.
  • Fish are ‘twitchy’ – a submerged line leaves no alarming surface wake when you retrieve it.
  • You want to keep your line out of the way of leaves or other floating debris (and the drag they cause) as it moves downstream.
  • You need your fly to be at a constant depth during the retrieve. The fly ascends when you retrieve a floating line, which can put fish off.

Sinking line

When you need to get your fly down fast to depths of 10 feet or more, you need medium to fast ‘sinkers’. They’re heavy, so awkward to cast but modern production methods have made them finer than they were, so casting isn’t the nightmare it once was.

Recommended if…

  • You’re fishing deep water.
  • The sun has brought too much light or warmth to the upper water layers, which has driven the fish deeper than they might normally be.
  • You want to fish delicate flies sub-surface but they’re too light to sink under their own weight.  

Sink tip line

A length of sinking line is attached to the front end of a floating line. That length can be a few feet or several yards and different sink-tip lines have different sink rates.

Recommended if…

  • You’re a novice targeting low-lying fish. The sink tip gets your fly down to them while the floating section is your visual aid to spotting takes, as explained above. 
  • With most of the line on rather than in the water, it leaves the water more easily when you want to re-cast.
  •  Patches of submerged weeds lie between you and the fish. The floating section remains above the weeds during retrieval.
  • Similarly, if the lake or river bed is ‘snaggy’, the floating section of a sink-tip line stays out of trouble.
  • If you’re fishing nymphs and want them just under the surface, a three-foot sink-tip section is perfect.

So, what’s with all the different colours?

You may well ask. One minute you’re being advised to employ the stealth of a hunter as you approach the water; the next you’re in a fly shop, looking at fly lines that come in enough colours for a hundred variations of rainbow.

While you can argue that all those line manufacturers can’t be wrong, there are still occasional warning voices from respected fishing writers that lines in darker, subdued colours are far less obvious to fish.  

Yes, you may have 15 feet of leader separating your line from your fly, and a trout’s so-called cone of vision only allows it to see what’s going on above it within a relatively small circle. 

Beyond that circle, however, it sees the river or lake bed reflecting off the underside of the water’s surface. Darker lines, say their supporters, blend into that reflection while light ones stand out.

Lighter lines are also said to reflect sunlight when cast in bright conditions, causing the dreaded ‘flash’ that sends fish for the exits.

Against this, a colourful line can be the fisherman’s friend…

  • If it’s gloomy, your eyesight isn’t great, or you’re fishing small flies, a colourful floating line points to the area in which your fly has landed.
  • As we’ve already mentioned, it can also give away the fish that’s pecking delicately at your fly.

The best advice is to have bright and dull lines to call upon but bear in mind the following…

  • The colour question is much less important in overcast conditions or when the water’s surface is so choppy that fish see very little of what’s happening above them.
  • If your bright floating line does seem to be turning fish off, your backup should be a natural colour – green, olive or brown.  
  • Once you’re fishing a line that ends up under the water, on the other hand, the debate is closed - you have to use muted colours.


Whether you're a seasoned angler chasing trophy trout in deep waters or a novice who is eager to explore the art of fly fishing, choosing the right fly line weight is your gateway to a successful and enjoyable experience on the water. At Flyshed, we understand the importance of a well-balanced setup, and our diverse range of fly lines ensures that you'll find the perfect match for your fishing style and target species.