Welcome to Day 3 of Sewing School!
Today, we are going to talk about thread tension. When I first started sewing, I had no clue what tension was or what it did. It seemed like something really overwhelming, and being mostly self taught, I figured I would never get an understanding and should probably just leave it alone. But then I started doing alterations for a local alterations shop, and the owner taught me all about tension. And guess what…It’s pretty darn simple!!!
You can adjust both the upper and bobbin thread tension, but anytime there is a problem with tension, you want to try to avoid adjusting the bobbin tension. You can almost always fix a tension problem by adjusting the upper thread tension. If you are ever in a situation where you have to adjust your bobbin tension, make sure you mark on the bobbin case where the tension screw was originally so that you can easily set it back in place when you are done. Also, make sure you make tiny adjustments. Maybe an 1/8″ – 1/16″ turn at a time & remember, it’s “right-y tighty, left-y loosey” (Is my dad the only one who used to say that?? lol)
So, what does proper thread tension look like???
Blue= Bobbin Thread
Now, please excuse my pic…my machine needs to be serviced pretty badly, so my stitches are a little slanted. But hopefully this will give you an idea of what you should be looking for. When your thread tension is correct, you should just barely be able to see a dot of the upper thread on the bobbin side and vice versa. When it’s too tight, the bobbin threads will show quite a bit on the upper side of the fabric, and may even cause your fabric to pucker. When it’s too loose the upper threads will show on the bottom.
There are a quite a few factors that can cause thread tension to be incorrect. First, make sure your machine has been properly cleaned according to the user manual. I clean my bobbin case after every sewing project. You would be amazed how quickly lint builds up in there! I also do a large scale cleaning of my entire machine about once a month.
“The pictures above show the same needle at increasing levels of magnification. As you can see, this needle appears sharp, even under low magnification, let alone the naked eye. However, this needle could cause all kinds of trouble.”
You also want to be sure that you are using a sharp needle. You should change your needle after about every 4 hrs of sewing. I usually change my needle after every project or every other project. It just depends on the project, and how much stitch time is actually involved. Not only can a dull or bent needle cause tension problems, it can also cause skipped stitches and damage your sewing machine.
Next, check to make sure your upper thread and bobbin are done correctly. If everything checks out and your tension still is incorrect, slowly adjust the upper thread tension knob/dial/whatever your owners manual calls it. I always move slowly…about half a number at a time. If you tension is too tight, decrease the number. If your tension is too loose, increase the number.
Ex: If your upper thread tension dial is on 4.5 and your tension is too tight, start by moving it to 4 go a few stitches, and if it’s still not correct, turn it down to 3.5, and so on and so on…
1) A heavier/lighter weight thread. I usually use your basic every day dual duty thread (the pink thread) for both the upper thread and bobbin, so I rarely have to adjust my tension, but sometimes if I am hemming jeans or doing some sort of decorative stitch, I will use a different weight of thread like the metallic thread (gold) or the denim thread (gray) pictured above. A heavier weight thread, may lag a bit especially if you are not using the proper needle. If the hole in the needle is too small for the thread, it can cause extra tension. Likewise, a lighter weight thread may slip through more easily and you may need to tighten the tension.
2) Different weights of thread in the bobbin and upper thread. If you are doing decorative stitching, etc and using a more expensive metallic thread for example you may want to use a bobbin thread (not the thread loaded in your bobbin. It’s a thread you can buy on a spool called bobbin thread. It’s an inexpensive and light weight thread; often used for machine embroidery) If the upper thread and the thread in the bobbin case are different weights, this can cause your tension to be off.
3) Sewing different weights of fabric. This is usually for quilters who may be using fabrics of different thread counts and weight + a batting. Of course, this could also be true if you are sewing a jacket, pot holders, purse, etc, etc…
I guess that’s it for class today! Hope it was helpful! As usual, please ask all questions in the comments section so everyone can benefit, and any additional input from other seamstresses is appreciated!!! And if you are new to Wildflowers & Whimsy please consider following along so you can keep up!! Happy Thursday!