Overlockers are basically finishing machines, mainly used for hems and seams but can also have decorative stitching options. The main benefit of an overlocker is that it can sew a seam, finish the edge and cut off the excess fabric in one step. An overlocker can be very useful if you only want to do simple projects such as making curtains or taking up hems but does not have the versatility of a sewing machine. It cannot, for example sew buttonholes or zips. Overlockers give a more professional finish to garments and projects. They are also great for sewing knitted fabrics, making a useful additional item, especially if you sew frequently. Overlockers are also known as “sergers”.