I typically do not use emboidery thread for the quilting, most types are not a strong as a cotton or poly thread. Look at the fiber content of the emboidery thread. Most rayon thread have great sheen , but lacks strenght. Embroidery thread is intended to be decorative, and most brands will not hold up to the stress on the quilting.
A factor in the breakage can also be how far apart you are quilting. If you quilt a good distance apart , when you are using the quilt and tug on it to repostion the quilt , grabbing the top , you can put alot of stress on that single stitch( quilting) line. Quilting closer together , can distribute that stress over more threads.
I would stress test my threads by pulling from each end before quilting , to ensure the thread can stand up to the use in the quilt.
Another factor is the needle size you are using. If the needle is small , there could be some shreading ( not quite enough to break while quilting) but enough to shorten the life of the thread in the quilt.
Last edited by Lori S; 12-12-2011 at 07:51 AM.