Originally Posted by gailmitchell
Usually you would find a french seam in heirloom sewing. Rather than starting out with right sides together to make the seam, you start out with wrong sides together to make the seam. Trim the seam down. Then turn it right sides out and make the seam again, which will enclose the first seam. There are several tutorials on the net.
If the finished seam line is at 5/8", I take a 1/4" seam with wrong sides together, press, then take a 3/8" seam with right sides together for a total of 5/8" to meet the given seam allowance.