In February for this year, I spent the whole month talking about different kinds of thread.

I mentioned that Superior thread Company has a terrific newsletter and that you all should subscribe to it.

Here is a exert from this months newsletter that I thought was very useful information and I wanted to share it with you if you haven’t yet subscribed to this wonderful newsletter.

I love knowing how stuff is made and how it works, I bet you do to.


A perfect seam is the goal of every sewing project. Many factors must work together in harmony to obtain the desired result. The machine and proper needle must be in good condition, the thread must lie smoothly and evenly in the fabric, and the tension must be set properly to accommodate the thread type, size, and any differences in the top and bottom threads as well as fabric and batting type. We will assume the machine, needle, and tension settings are all OK and focus here on the importance of thread quality, and more specifically, cotton thread for piecing and quilting thread.
There is a very wide range in the quality of cotton threads. Quality is determined by two factors:
1. the quality of the raw material (cotton fibers), and
2. the methods of processing
Fiber Quality When piecing, the finer and smoother the thread, the better the seam will appear. Some piece with polyester because it is so smooth and free of lint. The risk of using poly is when ironing the seam and possibly melting the polyester thread.  Although it is fine to piece with polyester thread as long as you exercise caution when ironing, our preferred piecing thread is a #50 high quality cotton.
Hold up some cotton piecing thread to the light and examine a few yards of it. If the thread is very fuzzy, or has slubs (clumps of excess lint spun into the thread), or is not consistently smooth, it is not a high quality thread. A low quality thread will produce a bulky and uneven seam.  It will also create a lot of lint in your machine.
On the opposite extreme, if the cotton thread is slick with absolutely no fuzz, that is also not a good thing if you will use it in a machine. The only way a cotton thread can be totally free of fuzz is if it is waxed or glazed with a coating to cover the fuzz. If cotton thread has a hard and shiny coating or wire-like stiffness, it is a glazed thread. Some coated cotton threads are labeled ‘glazed’ or ‘coated’ but unfortunately, most coated cotton threads are not labeled as such so it is up to us to know what to look for. Glazed cotton threads are intended for hand work only and are not recommended for any type of machine sewing. The glazed coating will rub off in the tension disk area and will gum up the machine. If you can see fuzz on the cotton thread, it is not a glazed thread. Non-glazed cotton threads are fine for both machine and hand work.
The higher grade the cotton, the smoother the thread and the lower the amount of fuzz. Cotton is classified by the length of the staple, or fiber. Labels on most cotton threads do not specify the staple classification because the majority of cotton thread is regular, or short staple cotton, and that is nothing to brag about on the label.
Low quality cotton  If there is no mention of staple length on the label, it is probably a short staple cotton. The cotton fibers are approx. 1.1 inches long.  A low grade cotton thread that is not consistently smooth and has excess lint will not create the best seam. The slubs and excess fuzz in the thread will create lumps in the seam. The slubs also get snagged in the tension disk and in the eye of the needle resulting in lint and thread breakage.
Medium quality cotton  Long staple. The fibers are approx. 1.25 inches long.
High quality cotton Extra-long staple (ELS). The fibers are between 1.4 and 2.0 inches long.  Extra-long Staple (ELS) cotton thread will be prominently labeled as such because it is a premium thread. You will be much happier using the highest grade cotton. Although it costs more, it is well worth it. A properly processed extra-long staple cotton will have very low lint and will be a much stronger thread. This means less breakage, frustration, and down time. A fine, smooth thread does not add bulk to the seams. It creates a much flatter seam which is especially important when sewing blocks which contain a lot of points. It is easier to use, will keep your machine much cleaner, and your finished project will look much better.
What about Egyptian cotton? This is one of the biggest lies in the textile world.  Egypt does not grow even 1% of the thread labeled as Egyptian cotton.  A hundred years ago, Egyptian cotton became the generic term for long staple cotton and today many cotton-producing countries deceivingly still use this term. That is why you may see labels stating “Egyptian cotton, Made in India” or “Egyptian cotton, Made in China.”
A true Egyptian-grown extra-long staple cotton is the finest cotton available.  It is subject to unique handling and treatment. To protect the cotton fibers from damage and rough handling, only leather-coated rollers are used in the cotton gins.
Cotton Processing    Although measure of quality is the staple length, processing also contributes to the quality of the thread.
Mercerized cotton  If you do not see the word ‘mercerized’ on the label, don’t worry.  The cotton is mercerized. Today, all regular cotton threads are mercerized, whether the labels says so or not.  Mercerizing is a process of putting the cotton fibers through a solution which causes the fibers to swell. This allows the dye to better penetrate the fibers, thereby increasing the luster and strength of the thread. How about some cotton threads that say “double mercerized”?  Our factory’s response was, “Why didn’t they just do it right the first time? There should be no need to do it twice.”
Polished cotton, silk-finish cotton, singed or gassed cotton are different terms for the same process.  A high quality cotton thread will be gassed.  This is a process of passing the thread through a flame at high speed to burn the longest hairs.  It results in a smoother, low-lint thread.  The label usually does not state that it is gassed because it sounds funny and it is not normally understood.  Hold the thread up to a light.  If you see a lot of fuzz or long hairs, it is not gassed.  If you see short hairs and little fuzz, it has been gassed.
Conclusion  As far as we have been able to determine, Superior’s King Tut (for quilting) and MasterPiece (for piecing) are the only truly Egyptian-grown extra-long staple, mercerized, gassed/polished cotton threads on the market.
We spend thousands of dollars on the machine, hundreds on the fabric, and it is well worth it to spend an extra few dollars to get the best quality piecing and quilting thread. You and your machine will notice the difference.And your family will thank you because you will be in a good mood.

Copyright © 2012 Superior Threads. All Rights Reserved. If you wish to reprint the Education portion of this newsletter, authorization is hereby granted as long as the source is clearly cited as follows: used with permission from Bob Purcell,

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