A rolled hem foot is specially designed to help you achieve tiny neat hemlines on lightweight fabrics. As you can see, there is a little spiral guide on the foot.
This is to tuck your fabric edge into a neat fold just before it goes under the needle.
You will see this hem on things like napkins, bandanas, and formal dresses in satins or chiffons. This size of hem is very hard to achieve neatly with simple pressing because it is so small. And many of the fabrics it is appropriate on are not able to be ironed or pressed.
My girl Taylor came home with a few new maxi dresses from Nanny and Papaw a few days ago. They were all so cute on her, but all but one were way too long. Enter the rolled hem foot!
This dress was made from super stretchy knit, so I was a little nervous about how the rolled hem foot would handle it. Fabric like this can have a tendency to get sucked down into your machine with a standard zigzag foot. There was no need to worry though - it handled it wonderfully! Now if this were not a maxi dress you would probably want to go with something more stretch friendly like a three step zigzag or a double needle stitch. But because the hemline has such freedom of movement this was perfect.
I cut the dress off just 1/4 inch longer than I wanted the final length to be. Then I hemmed the raw edge of the piece I cut off to make sure the fabric would work with the foot. It turned out great, so I started on the dress.
It can be a little fiddly to get your seam started, especially on a closed hem like a dress, so I recommend starting near a side seam if possible. Slide the edge of your fabric up and into the spiral guide. It will help keep it feeding in neatly if you hold the edge folded a bit over the left side of the foot.
Your needle needs to be in the center position, and you want to start with a slow speed and remain there until you are comfortable going a bit faster. It's important to keep your seam folded up as it goes into the foot. Keep your hand on the fabric to keep it from shifting and pulling out of the guide.
Two important tips to remember: make sure that the edge you are hemming is a smooth one. Look it over before hemming and make sure you don't have any jagged spots. The edge you are hemming also needs to be a clean edge. Trim any frayed threads before hemming or they will end up getting rolled into your hem and sticking out from it.
I sewed a few other fabrics to show you how it behaves with them. I'm working on a skirt for Lily using these fun mustache bandanas. But the bottom of the bandanas had this lettering that I wanted to get rid of, so I cut it off and hemmed it. This fabric did particularly well with the rolled hem foot.
This is a strip of satin that shows what happens if you have an uneven or frayed edge.
This foot did not come with my machine, but it is available at a very reasonable price. Mine came in this kit (not an affiliate link), which is less than $10 including shipping and includes 11 pieces.