where you will find lots of detailed information about sewing machine bobbins and more.
by Leah Day on her blog
365 days of Free Motion Quilting
Look after your dogs, feed dogs that is
on the blog Chubby Mummy
along with other tips and tutorials.
Bernina USA Sewing Trends Blog
(I use a Bernina, but otherwise have no affiliations with the company.)
From Superior Threads
Bobbin Tension – How to adjust and why it is important