Adjusting the tension in your sewing machine is the start point for making beautiful sewing, tension in sewing machine is adjustable because you need to sew different fabrics with variety of thicknesses, and different stitch length too.
The goal of adjusting the tension is to have your two threads meet in the middle inside the fabric, if the bobbin thread is showing on the top of your fabric then you need to loosen your tension moving to a lower number, or in some cases tighten the bobbin tension. On the other hand if the top thread is showing on the backside of your fabric that means you need to tighten the tension for the needle thread, or loosen the bobbin tension.
sewing machine tension problems
To find out which thread tension needs to be adjusted, you have to look for both threads and find if any of them is very tight, this means you need to loosen it’s tension first, otherwise go loosen the other one. You are going to have to experiment and see how your machine works with each kind of thread.
Having the too simple principles of stitch length and depth in mind, you should lower the tension whenever you are sewing heavy materials, this allow the machine to have longer thread for every stitch, that’s how the thread will be able to go throw the material and come back again at the end of the stitch. Sewing long stitches require loosen the tension for both the upper thread (needle) and the lower thread (bobbin) too, and short stitches obviously will require to tighten the tension.
To minimize sewing tension problems, it is a good idea to use the same thread the needle and bobbin too, using the same color is a good idea too to hide little problems and give it a professional look