In the 1996 summer issue of the Fly Tyer, Bill Merg and I co-authored an article on the subject of thread. The article appeared again in the November/ December issue of the British publication Fly Fishing and Fly Tying with a couple of additional threads added to the data. We worked on this article for about one year including all the research and testing of 72 different fly tieing threads.

The subject of thread strength vs. Size, and the accuracy of the numbering system (3/0, 6/0, 8/0, etc.) used by distributors and manufacturers had long aroused my curiosity. Based on my experience in using a variety of thread brands and sizes I didn't think the assigned size numbers were comparatively accurate. I thought that some manufacturers/distributors were using the good old "approximate" system. Our tests proved that three is no standardization in fly tieing thread size. Perhaps this variation was a case of oneupsmanship to try to achieve an advantage in the marketplace. Those making these decisions also may have felt the use of denier would not have been readily understood or too confusing for the customer. Bill Merg has subsequently published another article in the summer issue of Fly Tyer proposing to the industry a method for standardizing thread. I wouldn't hold my breath waiting for the industry to follow his recommendations. I think we will see the dinosaurs return before that happens!

In the textile industry denier is the standard method for measuring thread. Actually, there are a number of denier definitions, however, the one most commonly used is the weight of one gram for each 9,000 meters of thread. For example, Danville's 6/0, a commonly used thread for salmon flies, is rated at 70 denier. WAPSI Fly, Inc. is introducing two new threads in the fall of 1998 called "Ultra Thread". The smaller of these two threads that would be suitable for salmon flies has a denier rating of 70 as well. It is, however, five ounces stronger that 610 Danville. WAPSI is using the denier system to describe the new thread size rather that the traditional number system. Tom Schmuecker of WAPSI is trying to put some sense into thread sizing. The "Ultra Thread" is described later in this article.

Most of the threads used in fly tying today are made of nylon or polyester. Nylon has a little more stretch than polyester. I have never had any preference for one over the other. There are also a few threads made of Dyneema (Spun gel polyethylene) which also may be suitable for salmon flies. Even though these Dyneema threads are of the suitable thickness or fineness, plus they lay flat, their strength is well beyond what is needed to tie classic or even hair wing salmon patterns.

Waxed vs. Unwaxed thread always generates some discussion among salmon tiers. I have not found one to be particularly better than the other, but I've spoken to several tiers who prefer the waxed version because there is far less change of the thread fraying. In the original thread article Kent Helvie, a well know Northwestern steelhead and salmon tier, is quoted as saying that he prefers the unwaxed 6/0 Danville because it spreads better. Different threads have different amounts of wax added depending on the process used during manufacturing. The content of the wax varies as well. Based on my experience some are noticeably more waxed than other. I don't find that particularly disturbing other than the lower part of the bobbin tube is clogged with wax from time to time. The choice of waxed vs. Unwaxed thread is more of a personal choice.

For salmon tieing there are only two types of thread construction that meet the all important criteria of laying flat. Those two types are the semi-twisted and flat, with most falling into the semitwisted category. The semi-twisted thread can be flattened by counter spinning the bobbin (right handed tier).

Until the 1950's silk thread was the only choice readily available for tieing any type of fly. With the invention of nylon thread, silk quickly lost ground to the newcomer and now very little silk is used. There perhaps are a few exceptions; those who are too stubborn to change or ant to replicate with great authenticity. Danville and Pearsall's still distribute silk tieing thread. In the tests that we conducted only the Danville was tested which is rated as 2/0 in size. This flat silk thread is twice the thickness of Danville 6/0 and also about twice as strong. The thread comes on 50 yard spools and the available colors are black, white, and red. It is a good idea to wax the thread to preserve it, even if you don't get the flies wet. Danville will not continue to carry the silk thread once their current supply is exhausted. There is not sufficient demand and the cost of restocking is too high.

Danville 6/0 has long been the choice of many tiers. I suspect this may be due in some part to being first on the scene. It has the characteristics required by the vast majority of salmon tiers. The most popular colors are primrose, black, white, and red. It is available in waxed and unwaxed versions. The thickness of 6/0 Danville is 1.5 (in thousands) and it has a breaking strength of 11 oz.

The following threads are relatively new on the fly tieing scene, particularly in relation to Danville products. Several years ago Gudebrod introduced fly tieing thread on a spool which is about 2" long. The elongated spool holds 225 years of thread. This spool required a special bobbin which was made available by Gudebrod, and later a multipurpose bobbin was introduced by Bernie Griffin of Griffin Enterprises. Frankly, the decision to go with that spool was a mistake. Even though the product is excellent the spools never caught on. These spools will eventually be phased out.

Gudebrod has since introduced a standard spool (100 yards) which is compatible with most bobbins. The only bobbin that it will not fit without modification is the Rite© Adjustable bobbin. That problem is easily remedied by reaming out the spool center with a 0.295 drill bit.

The two Gudebrod threads that I find work well for salmon flies are the 8/0 and 10/0. The 8/0 has a thickness of 1.8 (1000ths) and a breaking strength of 15 ozs. It is made of polyester, is moderately waxed, and flattens beautifully. In addition to the standard colors, black and white it is available in over 12 different colors that match the Borger Color System. The 10/0 is a real sleeper since the size number I believe is incorrect. It is actually more like a 16/0. The thickness is 1.0(1000ths) and has a breaking strength of 9 ozs. It is 1/3 finer than Danville 6/0 yet only 2 ozs less in strength. However, the strength is more than adequate to tie salmon flies. If you want minimal bulk and absolute slimness it tieing buts and bodies this is the thread to try. It lays very flat and can be spread. It is also made of polyester and is moderately waxed which I believe is essential to reduce fraying with thread this fine. The 10/0 comes on the standard 100 yard spools and is available in seven different colors.

Giorgio Benecchi Products of Italy markets three semi-twisted unwaxed threads in sizes 810, 10/0 and 12/0. Of these the 12/0 seems well suited to tieing salmon flies. It does lay flat and is the same size and strength as Gudebrod 8/0. This is a good example of how confusing the sizing can be. It is available in 100 meter spools in over 12 different colors. The 10/0 thread is only a fraction thicker than the 12/0, yet is 7ozs stronger. It is available in all the basic colors.

England's Gordon Griffiths introduced a new thread a couple of years ago titled "Sheer Ultra Fine" thread with a size rating of 1410. Our tests indicate that this thread is the same size and strength as Benecchi 12/0 and Gudebrod 8/0. It is lightly waxed polyester and is available in ten different colors.

The WAPSI "Ultra Thread" I mentioned earlier will be available in October 1998. It is available in two sizes, 70 denier and 140 denier. The 70 denier has a breaking strength of 13 ozs and has a thickness of 1.1 (1000ths). The 140 denier has a breaking strength of Of 21bs. 2ozs., and it has a thickness of 1.6(1000ths) or about 13ozs less than Danville's Flat Waxed Nylon. As another comparison Gudebrod 6/0 has a breaking strength of 1lb 15 ozs. The test of the new WAPSI threads were done by Bill Merg in February 1998 using the same method as was used for all of the other thread.

The "Ultra Thread" is made of nylon and has more stretch than I have ever seen in any thread. I would estimate the stretch to be 10%. It is definitely a great thread for the heavy handed tier. Of course, there are no heavy handed salmon fly tiers!! It certainty provides a safety margin. It has only two twists per inch and will lay absolutely flat. I have thoroughly tested this thread and am willing to say it can easily substitute for floss on your fishing flies. Even though both sizes are lightly waxed, they are subject to separation and fraying if not used carefully. But, the advantages of this new thread far outweigh any disadvantages. The colors are brilliant. The 70 denier "Ultra Thread" (red cap end for easy thread tag storage) is being made available in sixteen different colors. The 140 denier thread is being made in thirteen different colors.

Uni-Products of Canada has recently introduced a new fine thread ("Midge" marked on the label) which falls into a similar category of the Gudebrod 10/0. It is a 40 denier thread, unwaxed, available only in translucent white on a 200 yard spool. I have tested it and did a comparison with Gudebrod 10./0. Under a 21/2X magnifier both threads appear to be the same. The only noticeable difference is the UNI seems to have a little more stretch. The flattening and spreading characteristics of the UNI 17/0 is the same as the Gudebrod 1010.

The Dyneema (spun gel polyethylene) threads which could be used for salmon flies include Dynacord 8n ( Uni-Products markets the same thread unde the name Uni-Cord), Roman Moser Powersilk, and Benecchi Ultra Strong thread. These threads are incredibly strong for their size. All of these threads are designated as flat and they spread very nicely. Dynacord is lightly waxed, and Benecchi and Roman Moser are not waxed. All come on standard spools and hold 50 yards of thread. They are three to four times more costly that the other threads discussed earlier.

Dynacord 8/0 has a breaking strength of 2lbs. 13 ozs. And its size is 1.0 (1000ths). Compare that with Gudebrod (10/0 thread which is the same size with 9 ozs. Of breaking strength. Roman Moser Powersilk thickness is 1.3(1000ths) with a breaking strength of 2lbs. 6ozs. We have not tested the Benecchi Ultra Strong thread. But, I can say with a great deal of certainty, after using almost an entire spool, that its strength is comparable to the other two. It probably isn't necessary to use a thread this strong in tying classic salmon patterns. But, there may be a few tiers that feel the extras strength would be an advantage in certain situation.

With the continued growth of general fly tying we are likely to see more new threads come on the market in the future which may be used by salmon fly tier. I am a great believer in trying new products to see if they are better that what I am currently suing. If the new product is better, I usually don't hesitate to add the thread to my over-crowed inventory. In my own general tying and salmon tying I use Gudebrod and Benecchi threads. No doubt there will be certain situations were I will use the Ultra thread. These three brands provided at least nine different breaking strengths/sizes and a rainbow of colors. For hair bugs I find the Dynacord 310 to be unbeatable with a breaking strength of 7Lbs. 9ozs.

I think you will be pleasantly surprised with the performance of the threads I have described. Give them a try for your salmon fly tying as well as trout flies. I doubt if you will be disappointed. If you need more information on any of these thread, or have questions about other threads, please give me a call.

Editor's note: Chris has recently started to market a number of high quality materials for tying classic salmon flies. If you are in need please give Chris all call.