What is Stranded Cotton

What is Stranded Cotton/Embroidery Floss

I thought we could take a minute to talk about one of the most popular types of thread available on the market, stranded cotton.

I’ll be diving deeper into the different brands in a later post. But first, let’s learn some terminology for this wonderful thread.

What is stranded cotton?

Cotton embroidery floss (or “stranded cotton”) is a form of yarn that became available from around 1850’s onwards. They are now widely used for various types of embroidery, and are one of the most commonly used fibers in hand embroidery. Not only is it is widely available, but it comes in a massive range of colors and is affordable. It’s typically made of a mercerised threads which are loosely spun together so that they are divisible (meaning that it can be divided into single fine strand). A process which is called “stripping” the floss is used to separate the single thread from the floss. They are commonly Z-plied, S-spun, but not always.

Floss

Embroidery floss (yes, floss) is made up of individual, divisible strands of embroidery thread. The individual threads (strands) are typically Z-plied. They are then grouped together, (usually in a group of 6) and are then combined using an S-twist (are S-spun), so that they will come apart, separate, easily.

In a nutshell, all the strands taken together are called floss. Floss can be made of anything from cotton to silk.

Thread

When talking about embroidery thread, the individual strands are called threads. Thread is a single strand of non-divisible yarn. It’s either Z or S plied. So when all the stands are still twisted together, it can be called floss. When talking about an individual strand, it’s a thread. Non-divisible yarns, like perle, coton a broder or floche are also types thread.

Embroidery threads came into being circa 1812 when supplies of silk became unobtainable in the UK due to a blockade by Napoleon. It was around then that cotton thread became available to the hand sewers in the United States and Europe. Before that, textiles were sewn with silk or linen thread, and rarely homespun cotton or wool thread.

Divisible

Stranded cotton by definition mean you can easily separated the strands into individual, non-divisible single threads. This allows you to customize the thickness of the stitch by choosing how many strands you want to work with. Most brands are made up of 6 loosely twisted threads.

Mercerized

In 1850, while studying in Leeds, England, JEAN DOLLFUS-MIEG’s son (heir to what would become DMC) discovered the invention of chemist JOHN MERCER, mercerisation, a process that involved treating cotton thread with caustic soda to give it strength, longevity and a silk-like lustre. Mercerisation is a treatment that consists of immersing the yarn or fibre in a solution of sodium hydroxide(caustic soda) for short periods of time, usually less than four minutes. The material is then treated with water or acid to neutralize the sodium hydroxide. If the material is held under tension during this stage, it is kept from shrinking appreciably. Mercerisation adds strength to the individual threads, creates a beautiful shine, and help keep the thread from becoming fuzzy and worn quickly (as long as it’s stitched with the grain, the correct size needle is used, is cut under 18 inches long)

Z-plied Vs. S-plied  & S-Twist vs Z-Twist

Our thread begins as roving. Roving are the fibers that have been prepared for spinning. It is not very strong in this state. So, the roving is spun into long pieces, called STAPLES, which “tangles” all the roving together making it stronger. Then two or more of those staples are then spun, or twisted, together to create a stronger thread, called a PLY. When talking about embroidery floss, the threads are plied/twisted two ways, S and Z. When they are plied together in an anti-clockwise direction, the resulting thread is called S-plied. If done so in a clockwise direction, it is called Z-plied. When threads are plied together, it strengthens the thread. Most cotton embroidery threads are S-plied threads.

It is a two-step process to create most embroidery floss. After twisting two or more staples together in order to create a single plied thread, those threads are then loosely twisted again, in the opposite direction to form the floss. Either with a S-twist or Z-twist. If the threads are twisted together clockwise, it’s Z-twist, counterclockwise it’s S-twist.

Generally, Z-plied strands are twisted together in a S-twist, and S-plied strands are twisted together in a Z-twist.

The direction the ply is formed is not always mentioned in the product information. For example, Sullivans just says their floss is “100% Egyptian cotton with reverse twist to provide virtually knot free and tangle free”. But many thread companies will tell you which direction the ply of their thread is twisted.

Most stranded cottons are S-plied, and then Z-twisted.

The plied twist of the thread is usually tight, but can be easily untwisted or twisted if the stitcher isn’t paying attention to the action of their hand while working. Keeping the correct twist while working is important. Remember how you sometimes have to stop and let your needle and thread dangle to right itself? If you keep stitching, letting the thread untwist, your thread will become fuzzy and worn looking. If it continues to twist more while stitching, the thread is sure to knot and it won’t lay as well on the fabric.

The ply of the thread doesn’t really make a difference for how stitches like satin and chain are worked. But other stitches, like stem stitch, french, bullion knots, etc., it can make a huge difference. When working a stitch, it’s usually assumed the thread is S-plied. But if it’s a Z-plied thread, certain types of stitches will look completely different or need to be worked in reverse (or in the opposite direction) in order to work the stitch correctly. For example, if working a stem stitch with a Z-plied thread, if worked like normal, the resulting stitch will actually be an outline stitch not a stem stitch. For bullion or french knots, the resulting stitch will have a different appearance depending on the direction the thread is wrapped around the needle. In the case of bullion knots, if the thread is S-plied and wrapped around the needle clockwise, the thread will maintain its twist and the resulting stitch will appear more well-defined, tighter and slanted. If the same thread is wrapped around the needle counterclockwise, the stitch will appear softer and more side to side because the thread is loosing it’s twist as you wrap the needle. In the case of stitches like bullion knots, neither way is wrong, it just depends on the look your going for in the stitch. It’s just something to be aware of.

Side note: Always be a bit wary of off brand threads. There’s a reason they’re so cheap to buy. They usually aren’t manufactured in high standards, the colors tend to bleed, the thread can become fuzzy and worn more quickly, are prone to knotting, as well as other issues. I always recommend buying quality materials. It’ll make your life easier in the long run.

Also, even name brand threads can sometimes bleed. It’s rare, but it can happen. If you’re worried about the thread bleeding, you can test a bit first. I’ll elaborate more about testing for colorfastness and how to set the dye in thread if they aren’t in a later post. But if you need that info now, just message me.

Lastly, I know how exciting it can be to find threads that are sold as lots off sites like eBay, estate sales, etc. But when buying any thread that’s been in someone else’s home, always quarantine the thread first. It’s hard to do, but it’s worth it. Place the threads into a gallon sized freezer ZipLock bag and store in the freezer for 30 days. Check on it every week or so. You’d be shocked at how prevalent critters like clothes moths are. And they will destroy the rest of your thread collection, not to mention any clothing or other organic fabrics in your home. And are extremely hard to get ride if once in your house. Alway error on the side of caution.

Quarantine Purchased Used Thread

Also remember that embroidery thread, especially when not stored properly, has a shelf life of around 10-20 years. Sometimes buying old, used thread just isn’t worth it. It’s too hard to know if it was taken care of correctly. It can stay usable and have a much longer shelf life if stores right, 50+ years. But few people take the time to store their threads right.