Have you ever wanted to know how to use your serger for more than just edge finishing? Then check out our FREE video series.

Last week we looked at the basics of tension and differential feed. Now we’re moving on to how to create gathers using these techniques. I did have someone mention that they didn’t understand some of the terminology so… we’re going to post a few pictures and notes. The video is in the next post. 

Just a Few Basics

If you have used a home serger or overlock machine you know that they can create a seam with a speed that most home sewing machines cannot match. Domestic sergers can sew at speeds up to 1500 stitches per minute while performing three tasks at one time. They can seam, trim excess fabric and overcast raw edges. All of this provides secure seams and a professional finished look.

Sergers are one of the most fascinating machines available to the home sewing market. Their creative potential is almost endless. This series covers several of the stitch patterns available on 4/3/2 thread sergers and how to use optional accessory feet. Our mission is to make your serger one of the most used machines in the sewing room.

Just a Little Terminology

Understanding the basic operation of the machine and a little basic terminology will help you get the most out of your serger. This is by no means a complete terminology list, but a good basic starting point.

What is a Looper?

A serger sewing machine differs from a lock stitch sewing machine in that it uses loopers and multiple cones of thread rather than a bobbin system. Loopers create thread loops that reach from the needle thread to the edges of the fabric to overcast or contain the fabric edges in the seam.

Upper Looper

The upper looper moves from right to left and passes behind the lower looper. Thread from the upper looper will appear on the top of the fabric in a balanced overlock stitch. This looper sits higher than the lower looper when machine needles are in the highest position.

Lower Looper

The lower looper moves from left to right and passes in front of the upper looper. Thread from the lower looper will appear on the back of the fabric in a balanced overlock stitch.

Upper/Lower Knife

The serger knife system cuts the fabric as it feeds through the machine. The knives are located ahead of the loopers and needles. The lower knife is stationary. The upper knife moves. The upper knife can be disengaged when cutting is not required.

Cutting Width

The cutting width controls the position of the upper and lower knives. Decreasing the cutting width means less fabric in the overcast seam. Increasing the cutting width means more fabric in the overcast seam. Cutting width affects the quality of the finished seam.

Stitch Finger

The stitch finger is a small metal piece that sits below the throat plate of the serger. The position of the stitch finger determines the amount of thread that will cover or enclose the seam. The placement of the stitch finger on some overlocks is controlled by the cutting width dial as the stitch finger has some bearing on the finished stitch width.

Stitch Length

Stitch length is the measurement from the start of one stitch to the end of the stitch and the beginning of the next stitch. Sergers generally have stitch lengths of between 0.5 to 5.0 mm.

Differential Feed

Sergers have two feed dogs. One in the front and one in the back.

Differential feed controls the speed at which the front feed dog feeds fabric towards the back feed dog.

Altering the differential feed allows the machine to gather or to remove puckering for knits and other fabrics.


We will be posting more on the serger – like basics of threading and Video 3. Don’t forget to leave a comment. We love your feedback.

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