Upper Thread Tensioning
Proper thread tensioning is essential to good embroidery. Too loose, your thread will begin looping; too tight, bobbin thread may begin to show on top and you may begin to experience frequent thread breaks which wastes time and money.
Before beginning your top thread tensioning, be sure to check your bobbin thread tension as this may lead to undesirable tension results of your top thread. Bobbin tensions should be 18 to 22 grams (up to 25 grams when embroidering caps).
A general rule of thumb is to have Rayon tensions at 100 to 120 grams and Polyester tensions at 120 to 150 grams. If you are using a specialty thread, such as Supertwist, it is best to lower the tension to prevent thread breaks.
Proper tensions for satin stitches should reveal 1/3 bobbin and 2/3 top thread color on the underside of the embroidery.
If you are still experiencing thread breakage after tensioning your bobbin and upper thread, be sure that your needles are fresh. Old needles may produce burrs and lead to frequent thread breaks.