Thread — The Stuff Which Holds It All Together

This would be me….

Whether you hand piece or machine piece, whether you prefer machine applique or hand applique, or whether you hand quilt or machine quilt, you must have thread.  Thread is the common denominator which ties all of quilting together. And after thirty-something years of quilting, I admit I’m a self-professed thread snob.  When I started sewing, there were only three thread brands available in my area – Dual Duty, Coats and Clarke, and Mettler.  Mettler was the best of the three. It was more expensive, and was only available at the one quilt  store in my area.  Time and experience taught me the Mettler was worth the extra pennies and the drive clear across town. 

As more fabric stores opened near me and with the upstart of internet sales, I became aware of additional thread brands and suddenly terms like thread weight, denier, and staple became important.  The more I learned, the pickier I became.  As a result, there are some brands I absolutely won’t purchase for machine or hand use.  With this blog, I want to discuss some general characteristics of all thread, and why I prefer certain brands for certain uses, and how I categorize the thread in my quilt studio.  For my long-time readers, I realize I wrote a blog on thread a few years ago, but one of the great characteristics of thread manufacturing is it’s always changing and improving.

First, let’s look into some general construction methods.  It’s worth remembering the higher the quality of thread the less special handing is needed.  Overall, thread is made from natural fibers (wool, silk, cotton, or linen) or from synthetic fibers (rayon, polyester, or nylon).  While there are literally dozens of fibers and fiber combinations which can be made, there are several common fibers used in quilting/sewing.

Spun Thread – Cotton or polyester staple fibers spun into single yarns and then twisted together.

Corespun Thread – Spun cotton or polyester staple fibers wrapped around filament polyester fibers.

Textured Thread – Polyester or nylon which has been mechanically textured to make thread fuzzy, stretchy, or woolly.  Texturing is a procedure and is used to increase the volume and elasticity of a filament yarn.  Textured yarns and those goods made from them are soft, have fullness, a high degree of elasticity, thermal insulation, and moisture-transporting properties. 

Filament Thread – Shiny thread made of polyester, rayon, or nylon strands.

Monofilament Thread – A single nylon or polyester filament.  Polyester is preferred over nylon.

Bonded Thread – A strength-enhancing resin is coated on the outside of the thread.  This increases the tensile strength and helps reduces friction.  Bonded threads are usually meant for upholstery and heavy-duty sewing.

Those are the common thread construction methods.  Now let’s talk about the common thread types.

Cotton Thread…sooooo many beautiful colors!

Cotton – This is the thread most used by quilters.  Cotton threads are made by twisting the fine staples (fibers) from the cotton boll to make a thread.  It’s important to understand there are different degrees of cotton quality.  There’s regular staple, long staple, and extra-long staple cotton.  The regular staples (fibers pulled from the cotton boll) are 1 1/8-inch in length.  Long staples are 1 ¼-inch long and extra-long staple is 1 3/8-inches in length.  The longer the staple, the stronger the thread and the less lint it produces.  That’s the great attribute about long-staple thread.  The downside is long staple thread costs more than the regular staple thread.  Overall advantages of cotton thread are:  strength, medium sheen, and the natural fibers help grab the fabric to create a tight seam.  There are a few disadvantages.  It’s difficult to tell high quality from low quality sometimes (I’ll give you a few pointers further down the blog).  The lint factor can also be problematic, however the longer the staple the less the lint. Cost can also be turn-off – quality cotton thread is more expensive. 

Corespun Polyester/Poly-Wrapped/Poly Core – These three names are used interchangeably for the same thread.  This thread has a filament polyester core which is wrapped in spun polyester.  This thread is strong, reduces puckering, and has excellent stitchability.  It produces low-to-moderate lint.

Filament Polyester – This thread is made from long, thin strands of polyester fibers which are twisted together.  The advantages of filament polyester are elongation (the fibers can stretch and recover) and smooth stitches with no lint.  However, the thread is not as strong as corespun (when considering the same size of thread) and finer filament polyester may require some tension adjustment on your machine.

Monofilament Polyester – Monofilament polyester is kind of like fishing line made for sewing.  It’s simply a single strand of polyester thread.  This is a very fine thread, blends well, and can be ironed on medium heat.  However, since it is so very fine, you’ll probably have to adjust the tension on your machine.

Spun Polyester – Spun polyester is made in a way remarkably similar to the way cotton thread is made – small polyester fibers are twisted together to make a long strand of thread.  This thread is less expensive to produce, so it will affect you less in the wallet than cotton thread.  Disadvantages to spun polyester are moderate-to-high levels of lint build up and it’s not as strong as filament or corespun polyester.

How Rayon is Produced

Rayon – This is definitely a thread of a different color.  Instead of twisting fibers together, rayon is created by pressing cellulose acetate (usually made from wood pulp) through small holes and solidifying it in the form of filaments. Rayon has several advantages:  high-sheen colors, softness, and it’s inexpensive.  However, it also has some real disadvantages, too.  It’s not always colorfast (it can bleed onto your fabric when washed, under UV lights, or when it’s exposed to bleach), it’s not as strong as trilobal polyester, and it’s not as durable as polyester. 

Nylon – Nylon threads are synthetic, just like polyester.  It’s often used in the form of a monofilament clear thread or a textured thread.  To be bluntly honest, this thread can give anyone a lot of problems. So much so that it’s not recommended for sewing of any kind.  The most-used version of nylon is a bonded version used in upholstery and other heavy-duty sewing.  This thread is made from a different type of nylon than nylon sewing thread. 

Metallic Thread

Metallic – Metallic threads are created from multiple layers of materials wrapped and twisted together.  The quality of this thread can range from very high to very low.  A good metallic thread does not require a lubricant.  A quality metallic thread leaves a beautiful sheen and has an excellent stitch no matter if you’re embroidering, quilting, or just sewing.  Usually there has to be some tension adjustments made when you’re using metallic thread and you may need to sew slower than normal.

Mylar Thread

Glitter or Mylar – Mylar threads are created by bonding thin layers of flat mylar material.  This thread can produce a holographic effect and can be used in embroidery, quilting, or sewing.  The disadvantages are the same as metallic thread – you may have to adjust your machine’s tension and you will probably need to slow down as you sew. 

Now that we’ve covered thread construction and the types of thread, we need to talk about thread processing.  All thread goes through much of the same processing:  twisting, lubricating, winding, etc.  However, cotton thread may have additional procedures done to it.  These extra processing methods will change how the thread is used as well as how it stitches. 

Mercerized – This is the process of immersing the cotton fibers in a caustic solution which will cause the fibers to swell.  Mercerization allows the dye to better penetrate the fibers and increase the thread’s luster.  Mercerized thread is also stronger than non-mercerized.  In today’s thread market, we can take for granted our cotton thread has been through this process, because nearly all of it is, even if it’s not stated on the label.

Gassed – When the label states a thread has been gassed, it means it’s been passed through a flame at high speed to burn off the longest pieces of lint.  This results in a smother thread with low-to-no lint, and it has a brighter sheen than its non-gassed counterpart.  Gassing is also called silk finish or polished cotton. 

Glazed or Coated – Glazed thread is coated with a coat of wax, resin, or starch and then polished to create luster.  The glaze makes the thread stronger than even mercerized thread.  This type of thread is not recommended for sewing machine use because the glaze can rub off in the tension discs and contact points as well as collect lint, fuzz, and dust which can cause a buildup in the thread path.  However, glazed thread is great for hand quilting.  I also use it in back basting applique. 

I realize this is a lot of information – I’ve written nearly 2,000 words at this point and I haven’t told you why any of this is important and where you can find it.  So right now, I want you to pause reading this blog and go grab a spool of thread with a label on it.  Go ahead…I’ll wait.

Got that spool of thread?  Okay.  Now look at the label.  Just like the labels on machine and hand sewing needles, there’s a lot of information packed onto the label of a spool of thread.  Keep that spool of thread nearby while you finish reading this blog. 


I’m using Superior Thread King Tut, Aurifil, and Mettler as examples.  These three brands are the ones I use most consistently in my machine piecing.  Hand sewing thread is a completely different animal and we will hit that hard in my upcoming blogs on hand applique.  On any label, you should be able to identify the thread manufacturer and the color of the thread.  The color is usually identified by a number.  With my King Tut, the number is 918.   The Aurifil is 2605, and the Mettler is 623.  The number is important – especially if you’re using the thread for topstitching or decorative stitching.  If you run out of thread and need to re-order or pick some up at the LQS, you know exactly what you’re looking for and it will match up wonderfully. 

The next item which should be readily available is the type of thread it is.  With these three, it’s plain to see they’re all cotton – but remember, I mentioned earlier most quilters piece with all cotton.  So, let’s take a look at some thread I use on my embroidery machine so you can see the difference. 


On the tiny label on the top of the thread, we see it’s 100 percent polyester and it even states it’s an embroidery thread.  However, even if the label had fallen off the spool of embroidery thread, I could tell it’s not a cotton thread because of the sheen.  We know from the definitions of the types of thread that polyester threads are brighter and shinier than cotton threads. 

The blue polyester embroidery thread has more sheen than a cotton thread

Another piece of information on the label is any additional process the thread has been put through.  Remember the additional finishing processes only apply to cotton thread.  So, if you’re using cotton thread, you will need to see if it is gassed, glazed, or coated.  A quick run-though of my thread inventory turned up no gassed thread, but a Google search found that Wonderfil Thread is gassed, which is plainly listed on the label. 

Gassed Thread

If you look at this label on a spool of Coats hand quilting thread, we fine the tern Glace’, which means glazed – so this is clearly thread we won’t use in our sewing machines. 

What you don’t see on any of these is the term mercerized because nearly all cotton thread is put through this process – so much so that most cotton thread manufacturers simply don’t put the term on the label.  You will still find mercerized on older spools of Coats and Clark Dual Duty, though.

In addition to these terms, you’ll find numbers, and just as with needles, these numbers are important. Some numbers are included on all spools of thread, and others aren’t.  The first crucial number is weight.  If you don’t remember anything else in this blog, commit this to memory:  The smaller the weight number, the heavier the thread.  A size 30-weight (30 wt) is larger than a 50 weight (50 wt) thread.  I could get into a lot of details on how thread manufacturers come up with weight, but it deals with a lot of metric measurements and would probably bore you.  Just keep in mind the smaller the weight, the heavier the thread.  The weight of thread you pick out will have a lot to do with the finished look of your quilt.  For instance, if you’re raw-edge machine appliqueing, you will want your thread to cover the edges of the fabric as much as possible to prevent fraying.  For this reason, you would probably want to pick a 40-weight or even 30-weight thread.  If you’re machine quilting and you want your stitches to really shine, again, you may decide to use a heavier weight quilting thread.  However, you wouldn’t want to use a heavier thread when you piece.  It’s important to keep the ¼-inch seam allowance as true as possible for accurate piecing.  You want to go with a higher number weight thread – such as a 50 or even 60 weight (60 wt. is my preferred weight thread for piecing).  Thread labels aren’t uniform, so you may have to look around for the weight.  And if the spool has labels on the top and the bottom, part of the information may be on each label. 

Another number which may be on the label is the denier number.  This is the weight in grams of 9,000 meters of thread.  If 9,000 meters of a thread weighs 120-grams, it’s a 120-denier thread.  Larger denier numbers are heavier threads.

Tex is an additional number which deals with the weight of the thread.  This is the weight in grams of 1,000 meters of thread.  If 1,000 meters of thread weighs 25 grams, it has a tex number of 25.  Larger tex numbers indicate it’s a heavier thread. 

The last set of numbers can be confusing, so I will try to explain them as clearly as I can.  These numbers are used on thinner threads, and they’re often mistaken as the weight, but it’s not.  The Number System or Number Standard was developed in Japan and is also known as the Gunze Count System.  For instance, if you see No. 50 or #50 on a spool, it doesn’t mean it’s 50-weight (50 wt) thread.  However, just like most of the other numbers on a spool of thread, the lower the number, the heavier the thread. It’s important to remember all the numbers don’t mean the same thing.  You may have a spool of thread stamped with 50 wt., No. 50, and 50/3.  All three numbers mean something a little different.  Don’t get too anxious about all of the figures and fractions.  Further down the blog I’ll tell you what I think are the important ones to remember. 

Finally, on most thread labels, you’ll see something like this:  30/3 (or 30/1×3) or 50/3 (or 50/1×3).  These are called composition numbers.  The first number is from the number system and tells us if it’s a heavier thread or a thinner one.  With these two examples we know the 30 is heavier than the 50.  The second number tells how many plies – threads twisted together – are in a strand of the thread.  Each of the examples has three plies.  As a general rule, the heavier threads have more plies than the thin ones.  For me, this is more important in hand sewing than machine sewing because the eyes of hand sewing needles are smaller than the ones on sewing machine needles and thus harder to thread.  It’s a whole lot easier to get 2-ply thread through the eye of a needle than 3-ply. 

Really good thread companies will also supply you with one more piece of information:  what size needle to use with the thread.  For instance, if you take another look at the label on my spool of King Tut thread:


You’ll notice it clearly states, “Use Topstitch #90/14.”  I know exactly what needle to have inserted in my needle mount before I make the first stitch.  However, if this information isn’t on your spool, the rule of thumb is you need to use a needle whose eye is 40% larger than the diameter of your thread.  To keep it simple, remember this – a 50 weight thread uses a 75/11 or 80/12.  A 40 weight uses 90/14, and a 30 weight needs a 100/16.  These are the three most used thread weights in quilting.  If you find your machine is skipping stitches or shredding the thread, go up a needle size. 

Okay.  I realize I just gave you a lot of information about thread – maybe more than you ever wanted to know.  What I’d like to do now is distill it down to what I believe are the most important items to consider on a thread label, where I purchase most of my thread, how I classify my threads, and the brands I prefer for different uses.  Again, let me reiterate, I do not work for any of these companies, nor do I receive any “freebies” for recommending them.

For me, the most important number on a thread label (beside the number which references the color) is the weight because the weight affects everything about the appearance of my quilt.  I want my ¼ seams to be as accurate as possible, therefore I don’t want the thread taking up a lot of room.  This means I will use a 50-weight or better yet, a 60-weight thread to piece with because they’re thinner and take up practically no room in a seam.  If I’m making a quilt which has raw-edge applique, I’ll use a thicker thread (30 wt or 40 wt depending on how I want the applique to look) to make sure the edges of the fabric are completely encased.  If I want my quilting stitches to melt into the background of my quilt, I’ll reach for an 80 or even 100 weight thread.  The desired appearance of any aspect of my quilt has the ultimate bearing on which weight thread I use. 

The second-most important number is the thread ply.  For this reason, I love labels which have fractions, such as 50/2 or 50/3.  For piecing, I want the thinnest, yet strongest, thread I can get.  If there is a 50/2 or 60/2 available, I’ll use it.  Same for hand applique – the thinner the thread, the easier it is to get it through the eye of the needle.  I use 2-ply or even 1-ply if I can find it. 

However, all my cotton thread has one thing in common:  it’s all long-staple.  Long staple thread is stronger and produces less lint.  If you’ve ever been in a situation where you have to go through the aggravation of re-threading your machine time and time again because your thread is breaking – you’ll learn to love and value long-staple thread.  And if you have a computerized machine, spare it the lint and don’t use cheap thread.  Plunk down the extra pennies for the long-staple thread.  Your machine will thank you in the long run.

Most of the time, my studio is humming with the long arm and at least one sewing machine.  I have multiple projects under my needle and multiple deadlines (even if they’re self-imposed).  Because of this, I don’t break down my thread by brand, ply, or weight.  I categorize it into three broad labels:  piecing thread, quilting thread, and machine applique thread. I have an area which houses all my piecing thread.  Since I favor 50- or 60-weight for this, all of the thread in that cabinet is one of those weights.  They’re also all either beige, light gray, dark gray, white, or black.  Piecing neutrals work with just about any quilt or color combination and keep you from having to change the thread to match the fabric.  My quilting thread is a little more complicated, but like my piecing thread, it’s all kept in one area.  My quilting thread ranges from 30-weight to the 100-weight Micro-Stippling thread from Superior Threads (one of my very favorites).  I use my quilting thread on both my domestic and long arm and it’s not hard to tell the higher weight from the lower weight.  What really comes into play with my quilting thread is appearance – how do I want my quilt to look after it’s quilted?  Do I want my stitches to really show (this calls for heavier thread) or melt into the background (the thinner the thread the better)? 

However, the one type of thread which is all over the thread-map is my machine applique thread.  Since I love both raw-edge and finished-edge machine applique, I have a lot of weights and colors. It’s difficult to keep them straight!  For this reason, I tend to keep them sorted by color and then by weight.  For instance, all my blues are together, and they will be put in a row from lightest to darkest and within that range, they will be grouped by weight.  For instance, my light blues will be together, and they start at 30-weight and go down the line to 80-weight (for finished edge applique). 

As I’ve mentioned before, after 30 some years of quilting, I am a self-professed thread snob.  Through trial and error, I’ve learned what brands work best for me.  At this point, I will mention which thread brands I consistently use and why.  Again, let me remind you, I receive no freebies and I’m not employed by any of names I’m about to mention.

Aurifil – This is my go-to piecing brand.  I can purchase it in 50- or 60-weight, and one of the best things about it is the spools are different colors for different weights.  A green spool is 40/2.  An orange spool is 50/2 and a white one is 60/2.  You don’t even have to read the label to know what weight you have.  It’s also 2-ply, which means it’s a great, thin piecing thread.  They also have a wonderful  brand of hand applique thread, and it’s on brown spools.

Superior Threads – Any type of thread, any color of thread, any weight, ply, or specialty thread is housed at Superior Thread.  They have great pre-wound bobbins and a wonderful piecing thread called Bottom Line – technically, this thread is for bobbins, but I’ve used it in piecing if I’m out of Aurifil.  Superior Threads have wonderful hand applique thread and equally fantastic quilting thread.  Almost any of their thread can be purchased in cones or spools.

Both Aurifil and Superior Threads are made from long-staple cotton.

If you want to purchase Superior Thread, you can go directly to their website:

You will find not only a seemingly endless array of thread and pre-wound bobbins, you’ll find needles, thread notions, and a terrific educational section.  Let me throw this in here – if you’re ever able to attend a workshop with Superior Threads, it’s well-worth your time.  Their customer service is second-to-none and I’ve never had to wait more than a day or two to receive my thread.

Aurifil is made in Italy, and it has a website, but individuals cannot purchase from the site.  The website has good information about their product, but for actual purchase, I love Red Rock Thread: This site is all things thread.  The selection is outstanding, and the customer service is stellar.  It also houses needles (both hand and machine in lots of different brands) and other thread notions. 

I hope this blog has at the very least given you a good overview about thread.  At the most, I hope it has explained my thread snobbery and maybe has produced a few coverts to join me.  Somewhere in the middle, I can only hope it gives you the information you need to make the right thread choices.  Thread is truly the factor which does more than hold and bind our quilts together and it just makes good sense to use quality thread to finish our projects.

Until next week, Quilt On!

Love and Stitches,

Sherri and Sam

5 replies on “Thread — The Stuff Which Holds It All Together”

I found this post very educational. Choosing thread has been mystifying to me ever since I started sewing again. Your explanations have helped. I still do not understand when to use polyester thread and when to use cotton. I asked my mother, who has quilted for decades. But she didn’t really have any good reasons of one over the other.

Honestly, now it doesn’t matter a great deal when you use polyester and when you use cotton. About 20 years or so ago, it was important to use cotton thread with cotton fabric because polyester thread would cut through the cotton fibers. Polyester thread has come a long, long way and now it doesn’t do that. Personally, I prefer cotton for piecing. But that’s a “Sherri Thing” and not a hard, fast rule. As far as machine applique or machine quilting goes, I use the thread which will bring me the visual results I want without regard to what the thread is made out of. Hope this helps a little. My advice is try different thread types and decide what works best for you. Thread isn’t a hugely expensive quilting item (when compare to everything else). If you piece a lot, get a spool of cotton and a spool of poly in a neutral and piece with both. Then decide what’s right for you.

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