When piecing, I generally like a smaller stitch length like a 2 to prevent unraveling on the ends and for better hold. Since I quilt mostly with batiks, my Coronet seems to prefer a size 16 needle. I usually use Aurifil 50 wt. thread, and Gutterman is well tolerated by my machine too. Due to the larger size needle, when I hold the finished quilt up to the light, it looks like perforated paper which kind of concerns me, so I make the stitches a little longer for strength, maybe like 10 stitches per inch. I know washing the quilt closes up the holes a little bit. Most of my quilts are for personal enjoyment.