A frequent complaint amongst quilters is “Help, my tension is off!”. What, exactly, is “tension”? What impacts it? and How do you “fix” it?
Tension is, essentially, the amount of thread that can pass from the spool to the needle (top tension) and from the bobbin to create the stitch. The more thread in the stitch, then the looser the stitch. The less thread, then the tighter the stitch. Both top thread and bobbin thread must be smoothly releasing your threads to form a stitch that lies flat on both the top and the bottom of your quilt, without puckering or thread loops. Top thread passes through tension discs, which control how fast the thread is released. Bobbin thread passes under a tension spring. No thread from the bottom should show on the top, nor thread from the top show on the bottom. On a quilt, your top bottom threads should meet in the batting.

What conditions impact tension (the variables) ? The not so great news is that MANY things can impact your quilting tension in addition to your machine top and bobbin settings.
- Your thread (type, condition, wind) may be causing tension issues…Is it old? Is it cheap? Is it rayon, poly or cotton? Are you using a MonoPoly, or a metallic? What weight is it? Are you using a spool or a cone? And what style of machine are you using it on? Have you tried a thread stand or a thread net to help it unspool evenly? Is your machine properly threaded?
2. Your needle…yes, I talk about needles a LOT because they are one of the most important and easily changed variables in good tension or a great stitch! Using the wrong size needle for your thread can cause tension issues or breaking and shredding. Change needles often!
3. Your fabric…What?? Yes, our fabric can impact tension. How closely woven is it? Does it have a plasticized “painted” color pattern (yes, this happened to me with a batik and was a nightmare). Is it pre-washed? Is it cotton or a blend? Is it silk or does it have a nap like flannel or minki?
4. Your batting… Batting can really impact tension! Cotton or wool will be denser than poly or bamboo. Bamboo is the most consistent in density. What loft are you using? It seems that with batting, even more than thread, a cheap batting can really throw off the tension.
5. Clean your machine...A clean machine is a happy machine! Lint build up in the machine, in the tension discs (YES, in between the discs) and under the bobbin tongue can ruin your tension as it adds extra drag to the thread passing through.
Controlling the variables: Use good quality thread, needles, fabric and batting. Sometimes saving a little money produces frustration and heart break when you start sewing. If you find a needle/batting/thread combo that works well, REPEAT it! TEST! Trying a new thread or batting? Using a dense batik or a looser weave lawn or voile or a napped fabric on top or bottom? Set up test squares to see how your combo works before putting the “real” quilt together. Check manufacturer recommendations for needles sizes for your machine (they are not the same for domestic machines and for long arm and sit down quilters).
Tension dials and bobbin adjustments: Machines all come (and come back from being serviced) with “factory settings”. This simply means that bobbin and tension dials are set so that tension is adjusted using common thread weight (usually 50 wt) and a double thickness of common fabric type and usually a size 12 needle (domestic) or size 16 needle (sit down quilter). (That little strip with stitches that returns with your machine after servicing.)



Any variation from these factors can require us to adjust our tension setting! For domestic machines with out auto tension settings, this means using our top tension. ALWAYS thread your machine with the presser foot and put the presser foot down before quilting. Domestic machines open the tension discs for threading, allowing the thread to fully seat the thread in the discs.For sit down quilters, there is no presser foot and the tension discs remain closed at all times. Your thread must be flossed between the discs to properly seat between them. Failure to floss the discs (or too tight top tension) can result in the thread floating on the top of the discs.

Righty tighty: lefty loosey! These words have helped me throughout my long life and they apply here as well. Turn your top dial right to tighten and left to loosen!
Bobbin adjustments, or rather the thought of them, can strike terror into the hearts of quilters. We were admonished to NEVER touch the little screw on the bobbin tongue. On a domestic machine using the thread weight/type that the factory setting uses, you may never need to adjust that tiny screw. But, what if you want to use Bottom Line or a thicker thread?? It may be necessary. Bobbin screws should be adjusted in tiny, 1/8″ increments. It is also okay to have more than one bobbin case and set them for your favorite weight threads! Righty tighty; lefty loosey.
Bobbin adjustments for sit down quilters (which are scaled down long arm machines) are an every day ocurrance as the PRIMARY tension adjustment is done on the bobbin using that tiny screw. Bobbin tension is set first and then top tension is adjusted if necessary. Tension should be checked with EVERY bobbin change (It takes just seconds!) Jamie Wallen has the best video on setting bobbin tension if you need a demo. I use prewound Class M Bottom Line bobbins and rarely need to adjust my bobbin tension or my top tension.
To sum up! What impacts tension? Our materials, supplies and the type of machines we use and their tension assembly systems. How to assure good tension? Use good quality and consistent thread, batting and fabric choices. When trying something “new”, TEST first. Change your needle often. Understand how your specific machine and how it functions. Your manual will tell you how your machine tension adjustments function.
Can you have a “bad” machine. Well, yes. BUT most tension issues are operator error and can be resolved. Start with the thread you wish to use and the correct size new needle and make a simple line of stitching on double thickness fabric. Is it good? If not, test a different cone or try a thread stand. Is the thread falling slipping to the bottom of the cone? Add a thread net. When it is good, add your batting and test again. Is it still good? If not, your batting may be the culprit. Some battings need to be “face up”, others can be sewn from either side.
I fiddled with my beautiful tension on my Tiara to illustrate a couple problems.




If you use a sit down quilter, like my Tiara ALWAYS set your bobbin first and then adjust the tension knob on top if needed.
Don’t try to change “all the things” at once if you are having problems. Go step by step. Test. Change one thing. Test again.
Happy quilting!
Lennea
HI what a brilliant blog , very informative and easy to follow. Thankyou
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