Interesting.... I had different results one day to the next... using the same spool of thread, same tension, same bobbin thread. Day one... everything looked great. I quilted a fairly large area with a free motion micro stipple using a 40wt thread on a slender spool. Day two.... (admittedly when the thread spool was getting pretty small) the thread was looping on the back side of the quilt. When I changed to a new spool of the same thread... all was well again. To my thinking.... this shouldn't have been a problem but for whatever reason, it was on this day.... Well... who knows when the point of no return occurs on a spool of thread but it was definitely worth the time to rip out and restitch. Judges (at least the skilled ones) do look at the back of art quilts.
"How do I rip out?" My trusty seam ripper slides under and cuts a stitch approximately every 3 stitches on the back side. Then from the front... my faithful slant angled LaCross tweezers (found at a beauty supply house or places like CVS pharmacy) easily lift the mess of thread fuzz without harming the front surface. In case you think your computer screen has a color correction problem, this picture is a different color thread in a different area. I rip out something almost every day. The good news: The more you quilt, the quicker you detect something is going wrong... so there's usually a few rather than a lot of stitches to deal with. Additionally, because much of my work gets judged, I'm getting pretty picky about what I will live with... or won't!