How to Choose a Sewing Seam Finish

Seam Finish Samples
Debbie Colgrove

The purpose of a seam finish is to prevent fraying and maintain the stability of the seam through numerous wearings and washings. Typically, you complete a seam finish after the seam is sewn, but you should choose the type of seam finish you will use before you sew the seam so that you can plan for the appropriate seam allowance. The type of seam finish you choose will depend on the fabric, the strength and type of seam, and the visual effect desired.

Types of Seam Finishes

Seam finishes can range from no-sew options to more elaborate techniques, but even the simplest finishes can effectively control fraying.

  • Pinked seam finish: This is a no-sew seam finish created by simply cutting the fabric with special scissors called pinking shears.
  • Clean finish: This is a simple straight stitch. It can be combined with a pinked finish (cutting the raw edge with pinking shears) for additional resistance to fraying.
  • Zigzag seam finish: This alternative to a straight stitch finish is made with a zigzag function on a sewing machine.
  • Flat felled seam: This is a double line of stitching that encloses the seam allowance into the seam so the allowance is not visible. It can be made with a sewing machine in one step (if the machine has this capability) or with a standard straight stitch machine.
  • French seam: This produces a clean finish that hides the raw edge. It is popular for lightweight and sheer fabrics.

Fabric Type

A fabric prone to fraying, such as a loosely woven fabric, will require more sewing in the seam finish than a tightly woven fabric that does not fray. Conversely, some fabrics, such as polar fleece, do not require a seam finish at all. However, in a garment, you may want to add a seam finish to “tame” the bulk of the seam. These basic finishes are suitable for most fabric types and where the seam will not be visible in the finished product:

Strength and Type of Seam

In most cases, a crotch seam on a pair of pants will take more abuse than a side seam on the same pair of pants. It is advantageous to secure the crotch seam with a seam finish that will strengthen the seam as well as prevent fraying.

A second row of stitching, as in a clean finish and a zigzag seam finish, will strengthen the crotch seam and prevent embarrassing moments:

  • Clean finish
  • Zigzag seam finish
  • Flat felled seam

Visual Appeal

Although seam finishes are inside the garment, there are situations where the seam finish will be seen. One example is an unlined jacket that is worn open in the front so that the inside of the jacket may be visible. A seam finish on such a garment should appear finished and have visual appeal more than the seams in a lined jacket:

  • Clean finish
  • French seam
  • Flat felled seam

Sewing Machine Limitations

Some sewing machines are not capable of sewing a zigzag stitch, but you can substitute with any seam finish that uses straight stitching:

  • Clean finish
  • French seam
  • Flat felled seam