Do you own anything with a lettuce edge hem? Typically seen on little girls' clothes, but often in women's clothing too, on the hemline of casuals and maxi dresses. This curly-wurly hemline looks pretty and is practical too, adding no bulk to the hemline and no fabric is turned up so if you are short on length, this is a good way to finish without making your project shorter.
How to sew a lettuce edge hem
Some knit fabrics stretch just in one direction, others stretch in both directions. To sew the lettuce edge hem you'll need to sew with the stretch. This is because the fabric needs to stretch as you sew and then relax back again to create the wavy finish.
You'll probably also notice that thinner knit fabrics have a tendency to curl on the edges. In this case, that's good because we are going to use that curl to our advantage. Take the fabric you intend to hem and stretch it. Which way does it curl, towards the right or the wrong side? You'll want to work with the curl of fabric on the top as you sew.
Cut a little of the fabric and do a test before working on your project to get the right machine settings. For mine, I used a stitch length of 0.3 and a width of 5.0.
Lay the fabric under the presser foot, and pull the fabric at the front AND at the back, trying to keep even pressure each side. This stretches the fabric and causes it to roll a little. Aim the center of your presser foot at that roll, and sew your wide but very short zig-zag stitch over the little roll of stretched fabric.
Once the fabric has had a chance to regain its original shape, the line of close stitching on the edge forces that edge to be longer now and so it curves and curls back and forth in a pretty wave.
I'm working on a new pattern, where making this type of wavy hem is an added option, so why not pick up some old scraps of knit fabrics and get practicing. It's addictive!