是来回缝的意思。主要用来缝合撕裂应力不是很好的布料。下面是英文的步骤：
Step 1
Make note of the of the difference between the “right” and “wrong” side of the fabric you are using. The nature of a French seam's construction requires that you be aware of the difference during construction so that they are properly oriented in each step.
Step 2
With the right sides facing out, pin material together, pinning entire length of edge where the French seam will be.
Step 3
Stitch a 1/4" seam allowance along the entire length of the edge pinned in Step 2. Remove pins after the seam allowance has been sewn. Note: contrasting thread shown in photo used for clarity only.
Step 4
Cut seam allowance (sewn in Step 3) to within 1/8" of stitches. Although you may use pinking shears, they are not required. The cut edges will be protected (and hidden) by the completed French seam.
Step 5
Unfold with the right sides up. Press entire length of trimmed seam allowance, pressing both edges flat and to one common side. DO NOT press seam open! Be sure to use a setting on your iron that will not damage the fabric.
Step 6
Fold material along newly created seam with wrong sides out.
Step 7
Press entire length of seam flat at fold on wrong side. Be sure to use a setting on your iron that will not damage the fabric.
Step 8
With wrong sides out, pin folded material together, pinning entire length of pressed seam created in Step 7.
Step 9
Stitch a 3/8" seam allowance along the entire length of the edge pinned in Step 8. Remove pins after the seam allowance has been sewn. Note: contrasting thread shown in photo used for clarity only.
Step 10
Unfold with the wrong sides up. Press entire length of seam flat to one side. Be sure to use a setting on your iron that will not damage the fabric.
Step 11
Give yourself a pat on the back. Note that the right side of the seam is neat and flat. On the wrong side, the cut (or pinked) edges of the seam created in step 4 are now concealed. You're done!
追问thank you for your kindly reply
Pls help to send me the mentioned picture for better understanding, many thanks