Called a rolled hem or rolled edge, this two-fold finishing technique is the neatest way to finish raw edges when you don't have access to a serger.
Ok, let's be real. It's just the neatest way to finish raw edges. Period. ;)
When I first started designing clothes, I didn't own pinking shears and my machine only did straight stitch, so I designed for the tools I had. My early designs incorporate more traditional finishing methods like French seams, fully-lined bodices, and this rolled edge. Now that I own a serger, these older finishing methods feel a bit more time-consuming, but hey, there's nothing wrong with slowing down and enjoying the process. Also the end result is a garment that looks just as good on the inside as it does on the outside, which you definitely can't get in any RTW that I can afford.
Also, if you're reading this because you are just starting out and your machine is a little janky and you don't have the cash to spring for a serger just yet - dude. You learn so much about sewing when you don't have all the bells and whistles. You're exactly where you need to be. :)
Anyway. I may yet design for serged edges - they can be pinked or zig-zagged - but in the meantime, I hope you enjoy an old-school finish or two.
When to use a rolled edge: This is the best hem and seam finish for delicate fabrics like lawn, voile, batiste, and silk. It's also great for lightweight fabrics like chambray, quilting cottons, rayons, and lightweight linens. Depending on the project, it'll probably be too heavy for twill, canvas, and other bottomweights - test it out before you make the final garment.
If you're using rolled edges to finish seam allowances, do so BEFORE assembling your garment. I use rolled edges to finish the center back edges of my dresses, but they're great for seams with pockets in them as well.
How to sew a rolled edge:
Start with your fabric, right side up.
Baste 1/4 from the edge.
Using your basting as a guide, press the fabric up 1/4" from the edge.
Fold the edge up another 1/4" and press. The raw edge is now all tucked in and hidden.
Stitch the rolled bit to the body of the fabric. You now have a nice neat finished edge that won't ravel!
This epic tutorial from Sew4Home covers rolled hems with a hemming foot, hems on delicate fabrics, and square corners.
Megan Nielsen shows you how to make teeny tiny rolled hems with a hemming foot, with a regular foot, and by hand.
Want a quick way to roll the edges on napkins or other home goods by hand? Check out this tutorial by Natasha on Felt Magnet.