Published Mar 24. 2017 - 6 years ago
Updated or edited Mar 11. 2023

Fly Tying Thread Options

Most fly tiers depend on their local fly shop for the thread, as well as other essential materials, to tie flies.

This article was written in 2003, and is published here as a part of Chris Helm's thread articles.
Some of the issues discussed here, spawned the article Fly Tying Thread Blues, and are covered in depth and with newer information in that article.
A huge selection - This is the impressing thread selection in Whitetail Fly Tieing - the shop formerly owned and run by Chris Helm
A huge selection
Joe Cornwall

Most fly tiers depend on their local fly shop for the thread, as well as other essential materials, to tie flies. Whatever thread brand the shop carries is what the tiers use, many times assuming this brand is quite adequate for what type fly is being tied. There is also the assumption that the shop owner is a knowledgeable fly tier and has tested various threads, and selected what is really in the best interest of the customer. Unfortunately that is rarely the case. The reality is that many fly shops carry what their primary wholesalers make available. Until about seven years ago, the two main thread brands available were Danville and UNI-thread. Once entrenched in the store most owners are not willing to add new lines or change brands for a host of reasons, including investing more money in inventory and not having additional space to display the thread.

As those of us

now who have been in fly tying for more than ten years, new and better products of all types have become available. At least five new thread brands have become available, all of which offer other options to what has been previously available. Are these brands better? The best way to find out is to purchase a few spools and do a comparison. These include Gudebrod, Benecchi, WAPSI UTC thread, Gordon Griffith Sheer thread, Roman Moser Power Silk, just to mention a few of the major brands.

You say that

your local shop doesn’t carry these brands. A little checking of mail-order catalogs will allow you to find them and a quick phone call will allow you to order a few spools and try them out.
What is different about these threads compared to those that have been around for many years? Numerous improvements including increased strength for comparable size, a broader range of colors, color fastness that doesn’t change when wet, the ability to lay extremely flat, super strength for tying bass bugs and large saltwater flies, thread stretch, and in some cases little stretch, a wider range of sizes (denier), and more accurate size designations.

Listed below is some information about thread which will increase your overall knowledge of this sometimes taken-for-granted material.

There is not a standardization

of thread size by distributor brand name. Size designations such as 3/0, 6/0, 8/0, are only for general use in determining the actual size of the thread. As an example, Gudebrod 8/0, UNI 8/0, Benecchi 12/0, and Griffith 14/0 are all the same size (thickness) and strength.

The correct standard for measuring thread is denier.

Denier is defined as a unit of fineness for silk, rayon, polyester, or nylon equal to the fineness of a yard weighing one gram for each 9,000 meters. As an example UNI 8/0 is 72 denier, Danville 6/0 is 70 denier, UNI 6/0 is 135 denier, Danville Flat Waxed Nylon is 210 denier, and WAPSI 140 Ultra thread is 140 denier.

Fly tying thread is made of

the following primary materials: silk, nylon, polyester, spun-gel polyethylene, monofilament, and Kevlar.

Nylon has approximately 25% stretch

compared to 15% stretch for polyester of the same denier. Gel spun polyethylene has 3% stretch.

There are four basic thread structures

, flat or continuous filament thread, simple-twist thread, rope twist, and round which is a monofilament thread. Each has qualities that are more appropriate for certain flies than others.

Some thread is prewaxed and some is unwaxed.

As an example all Benecchi threads are unwaxed and all Gudebrod threads are waxed. Continuous filament threads are better waxed than unwaxed to eliminate fraying. Danville Flymaster 6/0 is available in both waxed and unwaxed. WAPSI Ultra thread is available in waxed only. Waxed threads are not essential to make dubbing easier.

Select thread size and strength

in accordance with the size and material being used to the fly being tied. As an example consider Gudebrod GX 2 (gel-spun) for deer hair bugs, and Gudebrod 10/0 from midges.

Counterspin your bobbin holder

to untwist the thread after making a number of wraps. All semi-twisted thread will flatten if the bobbin holder is counter spun (right handed tiers). UNI 8/0 is a bonded thread which will not flatten even if the bobbin holder is counter spun.

Recommended thread for tying specific size and type of fly

Author recommendations are based on extensive experimentation. The threads are listed in order of preference. Size, strength, and color are all taken into consideration in making the recommendations.

Midges - size 18 and smaller Gudebrod 10/0, UNI 17/0, Benecchi 12/0, Griffith 14/0, Danville Spiderweb.
Dry flies - size 10-16 Gudebrod 8/0, Benecchi 12/0, Ultra 70, Danville 6/0, UNI 8/0.
Dry flies - size 4-8 Benecchi 10/0, Gudebrod 6/0, UNI 6/0.
Humpy size 10-16 Ultra 140 for body, Ultra 70 or Gudebrod 8/0 for wings and hackle.
Irresistible 8-16 Benecchi Ultra Strong for hair work, Gudebrod 8/0 or Benecchi 12/0 for wings and hackle.
Nymphs - size 14-20 Benecchi 10/0, Gudebrod 8/0, Ultra 70, Benecchi 12/0.
Nymphs - size 8-12 Gudebrod 8/0 or 6/0, UNI 6/0, Benecchi 10/0.
Nymphs - size 2-6 Gudebrod 3/0, Benecchi 8/0, UNI 3/0, Ultra 140.
Streamers - size 10-14 Ultra 70 for body and head, or Benecchi 10/0 for body and head.
Streamers - size 2-8 Ultra 140 for body, Ultra 70 for head, or Gudebrod 6/0 for body and 8/0 for head.
Muddler Minnow Gudebrod 6/0 for body, Gudebrod GX2 for head, WAPSI GSP 100.
Salmon flies
Hair wing salmon - size 2-8 Ultra 140 for body, Ultra 70 for head, or Danville 6/0 for both.
Special salmon (ex: Bomber, Green Machine, etc) size 2-8 Benecchi Ultra Strong.
Saltwater - size 2-8 Gudebrod 6/0, UNI 6/0, Benecchi 8/0.
Saltwater - size 3/0-2 Gudebrod AG, Danville flat waxed nylon, Ultra 140, Danville Fly Master Plus.
Bass bugs
Hair Bass bugs - size 5/0 - 8 Tail - Ultra 140, Gudebrod 6/0. Head - Gudebrod GX2 or WAPSI GSP 100. Head - Gudebrod 6/0.
Panfish flies
Foam panfish flies - size 8-12 Gudebrod 6/0, Benecchi 10/0, Benecchi 8/0, UNI 6/0.

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