Two separate settings that do two separate things, and confusing them is the usual reason a zigzag looks wrong.
Width is how far the needle swings from side to side, in millimetres. Zero is a straight stitch. Most domestic machines go to 5 mm, some to 7 or 9 mm.
Length is how far the fabric advances between stitches. Reduce it and the zigzags crowd together; at 0.3 to 0.5 mm they touch and become a satin stitch.
Useful combinations.
Edge finishing — width 4 to 5 mm, length 2 to 2.5 mm. Wide enough to wrap the raw edge, open enough not to draw it in.
Seams in knit fabric — width 1 to 2 mm, length 2.5 mm. A narrow zigzag gives stretch without looking decorative.
Appliqué and satin stitch — width 2 to 4 mm, length 0.3 to 0.5 mm, with a stabiliser underneath.
Attaching elastic — width 4 mm, length 2 mm, or a three-step zigzag which lies flatter.
Two practical points. Check the needle clears the foot before you sew: a wide zigzag through a straight-stitch foot or needle plate breaks needles immediately. And a wide zigzag pulls the fabric in from both sides, so on anything light the edge will tunnel unless it is stabilised or the width is reduced.
Write down what works for a given fabric. Zigzag settings are not memorable and the test scraps get thrown away.
Questions people actually ask
My zigzag pulls the fabric into a tunnel.
Too wide, too dense, or unsupported. Narrow the width, lengthen slightly, and put a stabiliser or tissue paper underneath.
Why does my needle hit the foot?
You are using a straight-stitch foot or plate with a swing stitch. Fit a zigzag foot and plate, and turn the handwheel by hand once before sewing.
Last reviewed 2026-08-11