I have had mine pucker, so I lengthened the stitch back to the 2.2 or 2.5. Too small of a stitch on a single layer of fabric will pucker on most sewing machines. It's okay when it hits a double or more layer but not on that single layer for me. I sew on two Brother machines, an inexpensive one from Wal Mart and an older embroidery one. Both of them do the puckering even though the embroidery/sewing is supposed to be able to sense the fabric thickness and adjust for it.