Originally Posted by
stitch678
The only time that seams pressed open are a problem is when you want to " stitch in the ditch". If you stitch on the sewing line, there is no fabric there... only thread. When l custom quilt a top with seams pressed open, l need to be careful to avoid quilting down those seams, and stitch next to them instead.
I wanted to add that a hand running stitch can't be pressed open, because there isn't a top and bottom thread for each stitch. The only way to cover the gaps is with a seam allowance pressed to the side -- so maybe that's where pressing to the side originated.