A: Looping on the underside, or back of the fabric, means the top tension is too loose compared to the bobbin tension, so the bobbin thread is pulling too much top thread underneath. By tightening the top tension, the loops will stop, but the added tension may cause breakage, especially with sensitive threads.
How do I stop my thread from tangling on my sewing machine?
Tangling Caused by Improper Threading
To correct this problem, put the presser foot up and unthread the sewing machine entirely. Rethread the machine with the presser foot up. Follow your sewing machine manual to make sure you are guiding the thread through all of the guides in the proper fashion.
What thread tension should I use for cotton?
Cotton requires a moderate tension setting, usually between three and four.
How often should you clean and lubricate the sewing machine?
The rule of thumb is to lubricate the machine after every three to four bobbin changes. Or clean and lubricate the hook area after each day of sewing.