A French seam is a type of seam finishing used in sewing where the raw edges of the fabric on the inside are totally encased in an extra row of stitching, creating a seam that is far more durable than most other seam finishes and an item or clothing pieces that looks as attractive on the inside as it does on the outside. French seams are generally used for lightweight and sheer fabrics such as silk, organza, and chiffon, where traditional seam finishing methods would show on the right side of the fabric. They are also great for items that will be washed repeatedly, such as pillowcases. French seams are best for straight edges and do not work well on curves, such as around the arms and neck of a garment. The basic concept of a French seam is that you sew the seam twice in order to neatly conceal any raw edges from view on the wrong side of the fabric, so basically, its a seam that looks neat on both sides. The following are the steps to sew a French seam:

1. Pin the WRONG sides of the fabric together.
2. Sew the first seam with a 1/4 inch seam allowance.
3. Trim the outside edge of the seam to about 1/8 inch.
4. Open the fabric so that it lays flat, then fold it over so that the right sides of the fabric are facing each other.
5. After folding it on the seam, iron it so that it’s perfectly straight.
6. Sew the edge again, using a 3/8 inch seam allowance this time.

French seams are easy to execute and can make any hand-sewn garment look professional.