Not all bobbins are created equal.
This inexpensive bobbin was fraying inside the bobbin case causing thread breaks.
When you find a bobbin that works for you, stick with it.
There are magnetic bobbins, paper sided bobbins, plastic sided bobbins to name a few.
We have seen success with paper sided bobbin, however we remove the paper. If the paper tears or if the paper has moisture it can cause a problem.
Our greatest success, along with many others, is with the Fil-Tec magnetic bobbins.
Magnetic bobbins have consistent tension with virtually no lint build up.