I used polyester invisible thread to stabilize my quilts with STID for quite a long time but then I tried Bottomline thread from Superior and I really prefer it. It hides easily, is flexible and much easier to see when I am doing the quilting. Another great plus is that it is much easier to tie off and bury the ends. I use a beige and light gray for this purpose. Sometimes I use this thread for decorative quilting also.