Setting the seam by “pressing” it (up & down, not “ironing” back & forth) might be a carry-over-thing from garment making (e.g. sewing a fabric with a lining). You want a balanced seam, no puckers, smooth/flat/even together, before you grade, all that, so setting the seam comes first before pressing-ironing it open, or to the side. Or, you might need a perfect scant seam allowance if doing a specialty seam, or an edge finish. I don’t normally do it when piecing a cotton quilt. But I might, with a curved seam, or if I graded something.
Last edited by Blondie~; 09-26-2019 at 12:40 AM.