Overlockers are also known as sergers. The name comes from the words "over" and "locker". The sewing machine has one thread on top of the fabric and another at the bottom so that it locks the seam. Another possible word for an overlocker is a "serger", which refers to both machines with overlock stitches, which also sew hems and trims.
An overlocker is used mainly for finishing seams by securing cut edges together. An overlocking stitch looks almost like a row of straight stitches bunched close together. It can be done manually or automatically. Meanwhile, you can also check out How To Remove Blue Stains On Clothes After Washing.
Manual means you pin or baste all the pieces together before sewing, then after each piece is sewn, take out the basting stitches. An overlocker also finishes seams with a serger stitch, which you can use to create various types of seams ranging from flat to fancy.
If you do not want any 3-thread finish on your clothes, then there is another option that employs four threads rather than three and gives a look similar to serged edges, but without serging them; this hides backstitching and reduces bulk.
An overlocker can be used for making decorative stitches around collars, sleeves, or on clothing parts like waistline or cuffs (if provided on your sewing machine). The decorative stitching on such places adds a flair of elegance and sophistication. A decorative stitch would also hide unsightly overlocking stitches if they were left visible.
It is also possible to achieve many other seam treatments such as French seams, flat-locking, and much more with an overlocker. Flat-locking is a process involving the use of zigzag stitches to hem or attach fabrics edge to edge, creating nearly invisible seams.
