Fly Tying Yarns & Flosses

What are fly tying yarns and flosses used for?

Yarns and flosses are wrapped around the hook shank or tied in as a short tail. They make bodies, wings (including parachute posts), tags and hot spots. Yarn is mostly used for wings and wing cases, but also for bodies. Floss gives a smooth body with a slight sheen – a good choice for wet flies and salmon flies.

Types of yarns and flosses

• Polypropylene yarn – lighter than water, and its fibres trap air. Use it for wings and bodies of dry flies, for wing cases and wings of emergers such as the Klinkhamer, and for hoppers and beetles. It is more durable than natural materials.
• Body yarns for nymphs and wet flies – blends of natural and synthetic fibres, e.g. wool and polyester. They give a translucent, slightly buggy body on nymphs, wet flies and caddis patterns.
• Floss – synthetic silk for smooth bodies on classic salmon and trout flies.
• Thick tag threads – for tags and short tails on nymphs, wet flies and small streamers.

How to choose yarn for your fly

First decide whether the fly should float or sink. For dry flies and emergers, choose polypropylene yarn. Wool blends absorb water and sink, so they suit nymphs and wet flies.

Choose the wing colour for visibility. White or fluo orange is easy to see from a distance, while grey and dun give a natural mayfly look. If you want a thicker body with fibres sticking out, use dubbing instead of yarn.

Tying with floss and yarn

Floss is made of many fine fibres, so it is easiest to wrap from a bobbin holder with a ceramic tube – or simply cut a length and wrap it by hand. Before wrapping floss, build an even underbody with tying thread, because every bump will show on a smooth body. A rib of fine wire makes a floss body more durable.

On a parachute fly, tie the yarn wing on the shank, lift it upright and wrap a few turns of thread around its base. This stiffens the post, so it holds the hackle wound around it. Trim the wing to length at the end.

Frequently asked questions

What is the difference between floss and tying thread?

Tying thread is thin and strong and holds materials on the hook. Floss is thicker, lies flat and forms the body or tag itself.

How long should a tag be?

A few turns at the hook bend are enough – just a few millimetres. A short, bright fluo tag often triggers takes from trout and grayling.

Do flies with polypropylene yarn need floatant?

It is not necessary, but dry fly floatant helps, and it is worth using when the fly starts to sink after a few fish.