A Short Course on Serger Buying
Sharon Stevens, Former Assistant Coordinator, Missouri Textile and Apparel Center,
College of Human Environmental Sciences, University of Missouri-Columbia

With prices ranging from a few hundred dollars to several thousand dollars and the number of threads ranging from three to ten or twelve, how do you decide what serger to buy?

The most important thing to is get one that will meet your needs. If you never do decorative thread work, you probably don't need a serger that has multiple decorative stitches. If you sew a lot of knit garments, then the coverstitch may be just what you need.

A serger, sometimes called an overlock machine, has a knife that trims the edge of the fabric and needles and loopers that form the stitches. Loopers are moving metal arms with an eye to carry the thread. The minimum is two loopers and one needle to form the 3-thread overlock.

There are six basic stitches common to sergers, but not all six are found on all machines.

1. 3-thread overlock. This is the basic serger stitch. Threads from an upper and a lower looper are held in place by the thread in the needle. The seam has moderate strength and stretch. When the tension is adjusted, this stitch will create a narrow rolled him. A second needle and fourth thread create an additional line of straight stitches down the middle of the seam adding strength to the seam.
2. 2-thread overedge. With this stitch the upper looper is converted to a hook that pulls the needle thread into an interlocking pattern. This stitch will bind the edge of lightweight fabrics and can be used to sew a stretch blind hem for knits. It also can create a fine rolled edge.
3. Flatlock stitch. This stitch creates a seam where the seam allowance lies flat to the garment instead of hanging loose from it. It is made by adjusting the 3-thread overlock or the 2-thread overedge stitch and can make an interesting embellishment when sewn with decorative threads in the looper.
4. 2-thread chain stitch. This stitch looks like a straight stitch on top and a thicker straight stitch on the bottom. It is rarely used for knits because it has little or no stretch. When elastic thread is used in the looper the stitch creates shirring. It will unravel if the lower thread is pulled, so it makes a good basting stitch.
5. 5-thread Safety stitch. A 5-thread serger can sew a 2-thread chain stitch and a 3-thread overlock stitch simultaneously. It is stable, non-stretching and appropriate for use on woven fabrics.
6. Cover stitch. This stitch is sewn with the knife disengaged. The two needle threads form two parallel lines on the front and the one or more loopers form a braided pattern on the bottom. This stitch can be used to sew a secure hem of any depth and is often used in knit tops. Variations of this stitch are available on more sophisticated machines.

The serger does not replace the regular sewing machine. It cannot sew a buttonhole or a zipper; it cannot topstitch, edgestitch, or make a blind hem. It can be awkward on curves. It can, however, save hours of time finishing edges, and parts of most garments can be sewn directly with the serger.

Bells and Whistles

Differential feed: Most sergers at every price level now have differential feed. Its function is to adjust the way two layers of fabric feed under the needle. When set to neutral, the two layers of fabric feed equally and, therefore, smoothly. It can also be adjusted to gather one layer on top of the other. It is also used to stretch or gather fabric for decorative purposes, such as lettuce edging.

Threading ease: Sergers are often hard to thread. They are fussy and the threading diagrams are sometimes hard to follow. Some models now offer features to make threading easier—snap-on and swing-out presser feet; color-coded threading charts; needle threaders; air-jet and/or self-threading loopers and other helps. These features do make threading easier; they also raise the price.

Tension adjustment: Unlike the regular sewing machine, the serger has multiple tensions to adjust – generally one for each thread in use. Additionally, different stitches are made by altering the tensions. Some machines have automatic and/or self-adjusting tension settings. Other models give you a chart or an LCD panel to help with correct settings.

Embellishment applications: On some sergers specialty feet are available for fagoting, felling, or attaching lace or beads and for other embellishment stitches.

Sergers may be mechanical, electronic, or computerized and prices vary greatly. The less expensive machines give you basic stitches, medium priced machines will give you many more stitches, features, attachments, and options. Some will have features to simplify the threading process and some will have optional feet for specialized jobs. High-end sergers require very little input from you. Many additional stitches are pre-programmed. Some will have memory for storing stitch settings.

When you go to buy a serger, take several weights of fabric with you and see how the machine sews on them. Ask the dealer to show you how to change to a rolled hem and/or a coverstitch. Think about how you will use the serger and which features will be important to you in the near future.

When your decision is made, inquire about sales, specials, and payment plans including 6- or 12-months same-as-cash. If you use the latter payment plan, be sure to pay it off before the deadline or you will owe interest on the full amount for the entire time period.