I use an embroidery needle size 11. I found that I was getting a lot of skipped stitches over the last few months, and that there was no difference with amount of skipped stitches with a quilting, topstitch or the size of the needle. I thought that my Janome was 'ill'; I read somewhere about trying embroidery needles; I did, and all was well. I use Gutterman thread.