Paul Procter

Fly Tying Thread Selection

Fly Tying Thread Selection

Fly Tying Thread Blog Posts

Fly Tying Thread Selection

Most fly dressers select thread purely based on thickness/denier (8/0 or 70 denier for example).  This necessarily isn’t a bad think as when tying small flies it makes sense to chose a finer thread, like Semperfli 18/0 classic waxed for example.  Of course, when tying pike/predator, or saltwater patterns then we’d aim for a thread at the other end of the spectrum, like Semperfli classic waxed 6/0, or even 3/0.

Just as important however, are the characteristics of a given thread and by that, we mean the way it behaves during tying.  Multi-fibred thread like Semperfli Classic waxed thread in 12/0, 8/0 & 6/0 has only a slight twist, so this lies flat (open) in its unused state.  The advantage of such untwisted thread is an even layer of thread is easily achieved now.  Something else, thread that lays flat has a greater surface area, making it ideal for securing materials like foam and deer hair that won’t be sheared off due to the increased surface area.

Photo 1:  Thread that lies flat in its raw state is perfect not only for creating a nice even base, but helps when securing foam and deer hair

Photo 2: Semperfli 6/0/8/0 & 12/0 classic waxed thread have a nice flat characteristic

Photo 3: Round in profile Semperfli 3/0 is just the job for tying large, robust flies like those used for predators, or saltwater.  

That said there are times when a tightly twisted thread is required, as possessing a round profile this has less surface area.  Instances where this might be necessary are when winding through palmered hackles to protect them.  Now, a rounded thread traps less hackle fibres.  Equally, when we come to complete the fly with that all important whip finish a rounded thread does not fray and ‘ball-up’ on itself, which can occur with thread that lies flat.

This of course doesn’t mean that a thread which principally lays flat is rendered useless.  In fact quite the opposite is true as by spinning your bobbing holder in a clockwise direction (when viewed from above) actually tightens the thread to make it round in profile.  Conversely, to take tension off again for you thread to lay flat, simply spin the bobbin holder in the opposite direction (anticlockwise).

So the question remains, why bother using twisted threads if we can tighten/untwist flat threads?  The answer really is nothing more than on certain patterns like north country spiders or those solely using thread bodies (the Gel Body Buzzer for example) a pre-twisted thread gives you the required and strength profile without the need to start spinning your bobbing holder.  Furthermore they remain in a twisted state at all times of the tying process.


Contact Paul For Guiding Or Tying Demonstrations

Paul ProcterResiding in Cumbria, Paul provides a guiding service for trout and grayling, fly casting instruction and fly tying lessons. As well accompanying groups to destinations throughout Europe and further afield, he travels the UK, presenting fly tying/fishing demonstrations and powerpoints. Paul is an Ambassador for Hardy Fly Fishing and Semperfli and Wild Fish (formerly Salmon & Trout Conservation) Vice President

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