I purchased prewounds that are plastic for embroidery.
that was is 2003 or 2004
I have a bobbin winder and have been reusing these ever since!
Sometimes you get one that cracks and I just toss it!
but I use 5-10 bobbins a day for piecing, just wind them all in the morning and I am set to go.No stopping and rethreading to wind a bobbin!
I have used them in every machine I have and not had a problem.