There was a post recently and not so recent that showed really great close up photos of thread from many of the makers out there. It was highly enlightening. This post caused me to go through all of my thread and sell my non-compatible treads. All of my rayon & polyester threads are for sale here: http://denver.craigslist.org/art/4037494130.html
This is the post that got me thinking: favorite tools aurifil thread
Which then led me to this post: your sewing thread under microscope
My response to those posts was... ahh, that makes total sense now. These 2 posts, I am sure there are more out there on the subject, confirmed what my hands were telling me. I am super picky about the fabric I use. I should have been better about the threads as well. My deepest apologies to the folks who have polyester thread for quilting and other parts. I was unaware. Now to have the funds to add the awesome Aurifil threads to my stash.