The process of sewing has evolved from laborious hand stitches with needles made of animal bone, to digital machines that allow the user to quickly and easily manipulate fabric and thread into complicated works of art. With each new feature and function, sewing machine selection has become increasingly daunting. The latest question on every sewing crafter's mind, be they novice or professional, is "Should I buy a sewing machine or a serger?"
Sergers, also known as overlock sewing machines, were originally used exclusively in industrial sewing settings. With the advancement of technology and the ability to create lighter, smaller machines that produce the same standard of stitch as their industrial brother, serger sewing machines have gone mainstream and can now be found in homes everywhere. What classifies a sewing machine as a serger? It's all in the stitch.
Modern sewing machines offer an expansive variety of stitches, but there are three fundamental stitching methods by which a sewing machine is classified:
The chain stitch method was used on the earliest sewing machines and involved only one thread and one hooked needle that mimicked a hand stitch. Though technologically advanced at the time, the chain stitch proved weak and could only be used for straight lines, so it was soon replaced with the lock stitch method.
Lock stitch machines are the sewing machines most often found in the home today. This stitching method utilizes a metal bobbin that sits beneath the stitch plate and holds a small spool of thread, while another spool of thread sits atop the machine. This top thread is passed through a tension mechanism, then through the eye of the sewing machine needle. With each revolution, the needle pierces the fabric and pulls the "top" thread below the stitch plate, grabs the "bottom" thread from the bobbin, and "locks" both threads and fabric together.
This is the stitch serger sewing machines use and its advantage is that it finishes the edges of fabric, utilizing built in cutters to trim excess, and an advanced looping method that leaves edges, seams, and hems clean, strong, and polished. The serger uses between one and five thread cones, depending on the desired stitch, and there is no bobbin. The thread cones feed "loopers" which loop thread that passes through the needle and around the fabric edge, encasing it entirely. Sergers are high speed machines, ideal for hemming, reinforcement, or construction.
Sergers are a great tool to have around if you do a lot of decorative sewing, work with stretchy or knit fabrics, or desire the strongest construction possible, but modern lock stitch sewing machines have a wealth of features also and will work just fine for most basic sewing needs.