Sewing Thread Part I: How Is Thread Made?


How is thread made? From magical worms, rows of cotton plants, or crude oil? Possibly all of the above! Did I just confuse the heck out of you? I promise to bring clarity, so stay with me. In this two-part thread series I will explain first how thread is made (so you know which to buy) and then in Part Two - which brands are the best quality and when to use what kind of thread.

As quilters, we would be lost without thread. But most of the time, we take it for granted. That’s why I’m doing a two-part series dedicated to thread: because it’s underrated, and it deserves some recognition. Dear, sweet Thread, we love you, we need you, we can’t sew without you!

In the first part of this series, we'll start with thread’s backstory, and talk about everything that goes into creating one of quilting’s major essentials.


Many sewists, especially quilters, have a favorite go-to thread brand that they know they can count on. Whether you’re partial to the Italian Aurifil or the German Gutermann, you know that it’s important to know and love and trust your thread.

Coats & Clark boasts almost 200 years of experience in the thread business, while Mettler claims that no matter what language you speak, their name is synonymous with high quality.

The truth is, all of these thread brands go through a pretty intense process before it’s ready to hit your bobbin. In order to do its job, thread has to be smooth, and friction-free. It has to be able to move easily, even when under considerable tension, and hold stitches even during washing and wearing. It’s a tall order.​

How Is Thread Made?​

Though the humble beginnings of thread-making started with hand-spinning plant fibers and strips of animal hide, the strong, flawless thread we know and love today comes to us compliments of the Industrial Revolution in the 17th and 18th centuries. That’s when the production of thread moved from the corner of the cottage to machines in big-time factories.

Because machine manufacturing made production waaaay more efficient, people could focus on making it stronger, prettier, and better suited to specific projects. Now, most thread is made from either silk, cotton, or polyester.​

How Is Silk Thread Made?​

If you’ve never heard about how silk is made, it’s pretty much the stuff of fairytales. Tiny silk worms feed on mulberry leaves until they begin to spin cocoons, secreting pure, silk thread from specialized glands below their mouths. (yummm!) The worms use the cocoons to transform into moths, but afterwards, the cocoons are harvested to produce silk (this is called schappe silk.)


The cocoon material is softened through washing and drying it. After a nice bath, the cocoons are passed through steel comb rollers to produce long, straight fibers called “combed top.” The combing process doesn’t stop there. The bundles of silk are combed and combed and fed through rotating rollers to twist them slightly (at this point, the emerging fibers are called “roving.” Lots of name-changes with the silk process.)

To finish the process, the roving is spun to form a single thread, which is combined with other single threads, and twisted onto a bobbin or cone. Meanwhile, the moths we stole from earlier are waiting for us in our attics to exact revenge by eating all our quilts when we’re not watching.

If you're more of a visual learner, check out this quick 5 minute video

How Is Cotton Thread Made?​

Cotton’s story is probably a little more familiar. Cotton grows on cotton plants, and can be picked, combed, and cleaned. After all the dirt and other plant materials have been sorted away, cotton fibers go through roller after roller to generate narrower and narrower bands of thread.

The narrowed-down fibers are then slightly twisted into “roving,” just like silk fibers, and spun to form a single thread. Cotton threads join up together to create thread of all thicknesses. That’s when they get to undergo a special treatment: cotton threads are singed over an open flame and immersed into a special elixir (it’s called a “caustic soda,” which sounds to me like Coke gone wrong…) and this strengthens the thread and makes it shine before it gets wound around a bobbin.

I used Cotton + Steel Sulky thread to sew a Hexie Stripe quilt - pattern available for instant download here. These threads are very high quality and come in tons of colors.


I saw this beautifully produced video detailing the collaboration between Cotton + Steel and Sulky Threads at Fall 2016 Quilt Market. Check it out for factory shots of the process of weaving Egyptian cotton into a spool of thread.​

How Is Polyester Thread Made?​

We call polyester a “synthetic” fiber because its origin story is a bit less natural. In fact, it’s pretty weird. We humans make polyester out of petroleum, the same original ingredient in gasoline. The process of modifying and producing thread out of petroleum has a lot to do with the extraction of chemicals, and a scientific process of refinement.

Polyester shows up to the thread manufacturer as “chips,” which are spun into long filaments to form “polyester tow.” Since we have a heavy hand in how tow is produced, it’s really long, with over 170,000 continuous filaments in a row. The tow is then stretched to its limit, and cut at its weakest points, so that only the strong fibers remain! The strong bands are combined to make a narrow, even, high-quality fiber, twisted up and stretched by machines until they are ready for their turn to be wound onto cones.​

Everything Dyes

After each thread goes through its own combing and twisting and winding process, they all end their birth story in a similar way: dyeing. At this point, we’ve totally mastered the process of dyeing and can produce hundreds of different colors. You won’t be surprised to hear that dye mixing is controlled by a computer, that releases just the right amount of dye for each group of thread it dyes.

Here’s a crazy fact: in one day, we dye over 6 tons of thread, which is enough to circle the equator five times. When I take a look at my thread stash, I think “yeah, that makes a lot of sense.”​

Whether it’s made inside of the bodies of magical worms, grown and picked from endless rows of cotton plants, or extracted from crude oil, all of our thread has been through a lot, and deserves some love and respect.

In the next post in this series, we’ll talk about the best brands and types of sewing thread out there, so before we get into picking favorites, we'll let every thread have its day. Click here to read Part Two!

34 thoughts on “Sewing Thread Part I: How Is Thread Made?

  1. Angela Short says:

    Thank you for educating me up on thread. I’ve often wondered how they make the polyester thread. There’s so many kinds and types and colors of thread that it can be confusing choosing thread!! Thank you again. Have a wonderful day!!

  2. Diane M says:

    Fascinating! It’s easy to take something like thread for granted so I enjoyed learning about the effort that goes into it’s making. Loved the video links and look forward to part 2. Thank you!

  3. Kerina says:

    Wow! I loved your article but the video regarding silk, wow!! It’s no wonder those moths come to eat our quilts, we killed there brethren 😂 I do love me some silk 💖

  4. Belinda says:

    Great post, looking forward to second installment and (hopefully) learning about the different uses of each type of thread… I’ve always used 100% cotton but curious if I should be using other types and for what purpose

  5. KC says:

    Wow, I grew up on a farm and picked cotton by hand. A very hard job and I appreciate the process of thread making. I love to quilt and love the smell of cotton. Thanks for this video. Look forward to quilting with this Cotton+Steel Sulky HD cotton thread.

  6. Paz valle donoso says:

    Me encanta todo lo confeccionado por Suzy los colores, sus explicaciones y he aprendido cualquier cantidad. Gracias y sus niños son unos encantos. Felicidades.

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