French seam is a bulky, finished seam that is great for delicate fabrics that fray. It is used on heavily washed garments such as lingerie and blouses. You will also find French stitching used on clothing for children and babies. It is found on children’s clothes for two reasons, one, so that the seam allowance does not rub against the baby’s soft skin. A traditional seam allowance will have a zigzag finish or a cut finish that can be rough on the newborn’s skin. And two, it holds up well with clothes that are washed often.
With a French seam, the raw edges are completely enclosed within the seam. It should not be used on bulky fabrics or curved seams. Unlike most seams made in making garments where the fabric is stitched together at the sides, French stitching is done by sewing the fabrics together with the wrong or ugly sides.
How to sew a French seam:
To sew a French seam, secure the fabric on the wrong side and sew a ¼ “seam allowance. Trim the seam allowance but be careful not to cut the stitches. Iron the seam allowance to one side.
Turn the fabric so that the right or cute side are together and roll the seam between your fingers and thumbs so that the seam line is right at the edge. Press plate. Sew in place.
Iron both the wrong side and the right side of the fabrics with the seam facing the wrong side of the garment. Note that there are no rough edges or fraying.