Thread is easily overlooked when starting a sewing project. As long as it more or less matches our fabric, sometimes we don’t pay much attention to it. But of course it really is a crucial component, whether we’re sewing a garment, a quilt, or a craft project — thread holds the entire thing together!
For a long time the conventional wisdom was that polyester or polyester/cotton blend “all purpose” thread was the “best” for garment sewing. That’s what I was taught when I started sewing in the 1980s/90s, so that’s what I used. For me, the results were not great. Seams were stiff and sometimes puckered. Yuck.
Everything changed when I read an article in Threads magazine in the mid-90s that discussed different kinds of thread and explained why cotton thread might be better for sewing on natural fiber fabrics. I tried it, was convinced, and have never looked back. Using cotton thread made a huge difference in my sewing and improved the quality of garments made with the soft natural fiber wovens I love to wear and sew. (This discussion applies to natural fiber woven fabrics only. Knit fabrics and synthetics have different requirements.)
The basic principle is that the sewing thread should not be stronger than the fabric.
Otherwise bad things can happen. When a seam is stressed, it’s better for the seam to break than for the fabric to tear. That’s pretty much all there is to it!
Why use cotton thread when sewing natural fiber fabrics? Polyester, a synthetic fiber, is stronger than cotton. So much so that polyester thread in seams can damage fabrics made of weaker fibers. It can also be inflexible in a seam; the stitches lack softness and don’t blend into the fabric. On the other hand, a soft, flexible cotton thread makes for a more supple seam that hangs better when worn. Shown above: my handloom cotton Azure Azur Dress stitched with Mettler Silk Finish No. 50 cotton thread.
Quilters apparently knew all along that cotton threads are best for natural fiber fabrics. After polyester thread became popular in the 1960s and 70s, supposedly some quilters found that stiff synthetic threads were cutting through cotton fabrics at the quilt seams. Imagine putting so many hours and so much effort into a quilt, only to find years later that one of its essential elements, the thread holding it together, had caused it to self-destruct. Quilts are meant to last for generations, so quilt makers think about things a little differently than do garment sewists. They preferred using cotton thread so quilt shops sold it even back when regular fabric stores didn't.
In addition, it's thought that synthetic threads can stretch when wound at high speed. That may explain the puckered seams I used to get before I switched to cotton — the poly thread stretched slightly when the bobbin was wound, then shrank back to its normal length when sewn into a seam. That's a recipe for sewing disaster!
Working at a textile supply shop in college gave me a further education in thread: even cotton threads come in a range of weights for different purposes. For many years my go-to thread was Mettler Silk Finish cotton, a 50 weight thread that I used for pretty much all sewing of wovens. In time, however, I found that lighter weight fabrics did better with a slightly lighter weight thread. DMC “Broder Machine” machine embroidery thread is a longtime favorite but it can be hard to find. Despite the name, it’s great for sewing delicate fabrics like silks and lightweight cottons such as our jamdani weaves. There is a no. 60 Mettler cotton that is similar, but even harder to find, and I have little experience using it. My Retro Tie Blouse, the ties of which are shown here, was stitched with DMC Broder Machine. The fine thread blends into the fabric.
Because I only sew garments from natural fiber wovens I nearly always use cotton thread. (The exception is when sewing heavy woolens, for which silk thread is a dream.) For many years I practiced couture sewing methods, using high quality fabrics and lavishing attention on details. This involved a great deal of hand sewing, which I love. Fine cotton threads are a pleasure to work with when sewing by hand because they’re so soft and malleable.
Living in an area without a local source for cotton threads, I learned to stock up whenever I found them. Once when the Mettler I needed was out of stock, a fabric store employee recommended Aurifil instead. (They told me that quilters love it.) I was a little skeptical because the no. 50 Aurifil is noticeably thinner than the no. 50 Mettler Silk Finish I wanted for general-purpose use. But I was very happy with the thread when I tried it. Since then I have used it extensively when sewing handloom fabrics like our Loom & Stars offerings, and on a wide range of other natural fiber fabrics, all with great results. Why is the no. 50 Aurifil finer than the no. 50 Mettler? The Aurifil is a 2-ply thread (referred to as 50/2), while the Mettler is 3-ply (50/3). The second number indicates how many plies of thread are twisted together to create the final product.
These are the threads I’ve mentioned, along with Gutermann cotton, which I find rather unpleasant to work with. Shown from left to right:
- Aurifil Maku no. 50: great for fine cottons and silks and all-purpose sewing on light/mid-weight natural fiber fabrics. Stronger than DMC.
- DMC Broder Machine no. 50: great for fine cottons and silks, but not very strong.
- Mettler Silk Finish no. 60: nice if you can find it.
- Gutermann no. 60: not for me. Stiff and heavy.
- Mettler Silk Finish no. 50: great for all-purpose sewing on mid-weight natural fiber fabrics. Makes a nice-looking seam.
It’s hard to see in the photo, but the Mettler no. 50 (on the right) is noticeably thicker than the Aurifil and DMC (on the left) when held in the hand. The thinner threads will sink into the fabric, like on the blouse tie ends pictured further up this page, while a thicker one like Mettler no. 50 will remain more visible on the fabric, as seen in the photo of the blue dress hem.
Generally speaking, the finer weight cotton threads make a beautiful, soft seam when sewn by machine, and are very pleasant for hand sewing. They may be too thin for topstitching, but edgestitching will blend into the garment. These threads are what I recommend for sewing handloom cotton fabrics, especially the lightest jamdani weaves, as well as block prints, voile, and light- to mid-weight cotton, silk and linen. We offer Aurifil no. 50 to match many of our fabrics so you can start your project right away and not waste time hunting for thread. Shop for Aurifil thread here.
(This thread may not be sturdy enough for heavy-duty garment sewing, bag-making, etc. These comments are based on my own experience, and for the most part I sew only lighter-weight garments.)
The finer cotton threads are also great for seams that require multiple passes of machine stitching, such as French or flat-fell seams or bound seam finishes, without making the seam stiff or heavy. They make beautiful machine-stitched buttonholes, too. The buttonholes pictured here were stitched with DMC Broder Machine thread in 2 passes. Needless to say, you’ll want to pair these lighter weight threads with fine needles, for both hand and machine stitching. Find needles and notions here.
Using cotton thread as I've described here has worked for me for several decades of garment sewing. Sure, I have occasionally stepped on a skirt hem and heard the thread break, but that’s far better than having a rip in my skirt. A seam can be re-stitched, while a torn garment might be irreparable.
Even something as seemingly mundane as thread can make a big difference in your sewing. Just as you sew test seams to check the sewing machine’s tension before starting a new project, you might sew some samples to try out different threads. How does each feel to sew with? How do the different seams look, and how do they drape with your fabric? There’s always more to learn as we refine our sewing skills. Try something different, test things out, and always question the conventional wisdom. Learning what works best for you (and your sewing machine) is a very rewarding part of the sewing journey.