The rolled hem, also known as a "roulé" is a very tight hem that involves winding the edge of the fabric over itself and stitching it with a straight stitch or a zigzag stitch.
It's often used on soft fabrics when you're looking to make a quick, thin hem.
The rolled hem is usually done with a serger.This is how it will be easiest to make. However, many of us don't own this little machine.
Rest assured, it is perfectly possible to make the rolled hem with a classic machine and, as you choose, a classic foot or a "hemming foot".
The practical thing about the hemmer foot is that it causes a rotational movement on the fabric, which automatically rolls up on itself. It can be stitched in straight stitch or zigzag stitch, for an even more "roll" effect on the edge of the fabric. Do a few tests on fabric before starting your work because the hemming foot requires a few adjustments (thread tension, stitch width...).
Traditionally, the rolled hem is made by hand. This is how, for example, pretty Finishings were achieved on a handkerchief or doily in the old days.
Be aware that this is a painstaking job that requires a lot of patience. To make a hand-rolled hem, you'll need a very fine thread and needle.
The roulotté takes about 1cm of fabric and is formed as you sew.You don't need to pin or build.
If you are right-handed, you will roll the roulotté between your left thumb and forefinger and begin sewing with your right hand. First a small stitch (A) just below the roulotté then a stitch (B) just above which crosses the roulotté 5mm to the left and comes out in stitch (C) and so on.