An Overlocker Tutorial

    by J.C. Lewis

    About the Author

    J.C. Lewis is the editor and co-owner of a weekly newspaper, as well as an editor for a group of newspapers in Los Angeles. Her writing has appeared on,, LIVESTRONG and Lewis holds a BSc in politics from the University of Bristol, England.


    An overlocker (also known as a serger) is a type of sewing machine used both industrially and domestically for seaming, hemming and edging fabric all in one pass. There are several different types of overlockers and they all have needles and fingers that stitch and loop multiple threads to contain the raw edges of a seam, while simultaneously trimming the edge of the fabric.

    Stitches & Uses

    Different models are able to create different types of stitches that are used for different purposes. Overlockers use 3, 4 or 5 threads, each from an individual cone. For some sewing needs, an overlocker is used alone but sometimes a regular sewing machine and overlocker are both used. An overlocker sews considerably faster than a regular sewing machine and eliminates some of the steps involved in regular sewing because overlocked seams are self-finished. An overlocker is especially useful when sewing stretch, woven and knit fabrics, which can be difficult to sew with a regular machine. The overlocker will feed all the layers of fabrics evenly and creates durable, stable seams. For tailoring tightly woven, non-stretch fabrics like linen and wool, a regular sewing machine is usually used for seaming, and then the raw edges of the seam are finished with an overlocker. The looped stitches created by overlockers can also be used for decorative effect.

    Practice & Tension

    Before using your overlocker for a sewing project, become familiar with the machine and know how to set correct stitch tension. You should be comfortable with the different stitches and techniques you need for a sewing project before starting it. Use a scrap piece of the fabric and sew a practice seam. If the stitches are all flat, neat and smooth, and looped into a chain along the raw edge with no puckering, the tension is correct. Otherwise, you need to adjust the individual tension for each thread until the stitches are perfect. Generally, if the threads are pulling towards the top of the fabric, the upper tension should be lowered; if they are pulling towards the back of the fabric, the lower looper tension should be loosened. If you are a beginner to overlocking you can learn how the machine works by using contrasting colors for each thread and spending some time adjusting the tension of each thread and examining the results. Consult the machine manual for instructions specific to your overlocker.


    To start sewing with an overlocker, make some stitches with no fabric in the machine until you have a thread chain a few inches long. Make a couple of stitches on the fabric, lift the presser foot and needle then bring the thread chain under the presser foot and along the seam line towards you. Lower the foot and needle, hold the chain along the seam line and stitch over it for about an inch, then hold the chain to the right to be cut by the blades. This creates a secure seam, similar to back-stitching on a regular sewing machine. Similarly, when you reach the end of the seam, lift the presser foot, turn the fabric over and stitch back over the seam for about an inch; finish by sewing off the side of the fabric. Run the machine to create a chain of a few inches, and then trim the end of the chain close to the fabric. To sew a French seam with an overlocker, sew along the edges with the wrong sides of the fabric together, turn the fabric right sides together and sew a line of straight stitches with a regular sewing machine. This hides the raw edges and is suitable for sheer fabrics. You can stabilize overlocked seams by fusing a narrow strip of interfacing to the fabric and sewing over it with the overlocker.