I use silk thread for hand appliqué and Aurifil for machine appliqué. However, I recently finished a Frozen quilt that had 22 large appliquéd snowflakes. I did not want the stitching to show so I used my #100 Kimono Silk Thread that I use for hand appliqué and a #60 Microtex needle. The stitching was almost invisible and I had no problem with thread breaking. I used Aurifil in the bobbin. Best wishes with whatever thread you use.