I've just finished quilting the quillow in cotton, used a cotton backing, and everything went wonderfully. Now am on to the final baby quilt which has a polycotton backing and I wanted to use a rayon thread but, guess what, the thread is breaking again.
I'm using a new but the same type needle and same settings. Its a nice variagated thread and not particularly thick so will go and persevere. I tried an assortment of needles last time when I had trouble jeans, quilting and embroidery, - perhaps I will try one of the needles from an unmarked box I have!