There are so many kinds of thread available on the market, so the choices can be overwhelming. But here are some of the most common thread types and recommendations for their use:
Polyester thread is strong and durable, colorfast, and has some degree of stretch to it. It’s a good all-purpose thread suitable for most fabrics and uses.
Cotton thread has less strength to it, so use it where little or no strength is needed, like topstitching. It also has little stretch to it, so don’t use it for knit fabrics or you may end up with broken seams. It also tends to produce more lint than polyester thread. Use it for light to medium weight, natural fiber fabrics.
Cotton-wrapped polyester thread
This thread has the look of cotton and the strength and stretch of polyester. It’s a good all-purpose thread appropriate for most fabrics and uses.
This is a strong, smooth thread that has some stretch to it. Use finer silk thread for delicate fabrics, medium for silk and wool, and heavier silk thread for topstitching. It’s also a good thread for knits.
This is a very strong thread appropriate for light to medium weight synthetic fabrics. It’s not very heat resistant, so be careful when pressing it.
What does the term "mercerized" mean?
Mercerization is a finishing process applied to cotton and cotton-wrapped polyester thread to make it smoother, give it luster, reduce lint, and to help it take dye better.
Threads are available in different thicknesses. Some, but not all, threads are labeled with numbers to indicate size. The lower the number, the thicker the thread. For general sewing, look for size 50 thread, which is a medium thickness. Choose thicker thread when you need more durability, such as when sewing vinyl or upholstery, or when doing topstitching. Use finer thread for lighter weight fabrics.
A few words about cheap thread…
Just in case you’re wondering, “Why should I spend $2.00 or more for a single spool of thread when I can get a pack of five spools for $1.00?”
Because cheap thread tends to be fuzzy. It will produce excessive lint that can build up in your sewing machine, causing wear and tear. And cheap thread tends to be nubby and weak, making it more prone to breakage – both in your sewing machine and in your finished item. So don’t skimp on thread quality to save a few cents. You’ll likely experience more problems in the long run.
So how exactly do you tell thread quality? Unwind a strand and hold it up to the light. A good quality thread will have very little fuzz. Next, run the strand through your fingers. It should feel smooth without any nubs. You may even want to buy one of those cheap spools of thread to compare, just so you can see the difference.
And seriously consider discarding your old thread. Thread can deteriorate over time. For instance, cotton thread can become dry and brittle with age.
To extend the life of your thread, store it out of the light (UV rays can cause thread to deteriorate) and protected from dust.
Matching the color
To match the color of your thread to your fabric, unroll a strand and lay it against your fabric – preferably in natural light. If you can’t find an exact match to your fabric color, choose one shade darker. It will appear slightly lighter once it’s sewn into your fabric. For a print fabric, match the dominant color.
Generally speaking, use the same type of thread for both your upper and bobbin threads. Using different threads can lead to stitch problems.
Before starting your project, test your thread first on a scrap of your fabric. Sew various stitches, changing your tension settings, stitch lengths, presser foot types, and pressure foot pressure. See if you like the way the thread looks and make note of the machine settings you like best.