The default setting on my Pfaff is 2.5, but I figure the smaller the stitches, the more secure, so I set it to 2.0 for piecing. I don't go any smaller than that because that's the smallest stitch I can easily unsew with the seam ripper. The 2.0 setting translates into 14 stitches per inch---I had to put on the Ott light to count for ya!
