Finish Curves with Bias Binding

Do you find curved hems tricky to finish neatly? There are some common reasons why it may be difficult: fabric is too stiff/thick, seam allowance is too deep, it takes more patience/pressing that some feel they have time for in a given project. There may be a host of other reasons, but I have a way today that is guaranteed to give you a neat looking curved hem with minimal frustration. It works on any curved edges, including necklines, sleeve flounces, and hems. All you’ll need in addition to your garment, machine, etc, is some single fold bias tape. Store bought or make your own…the choice is yours.

One of my biggest tips when working with bias tape is not to cut it in advance. Because it’s cut on the bias, it’s slightly stretchy. It is to be applied with a slight bit of tension…a very teensy stretch in order to prevent gaping. This is difficult to achieve when you already cut the pieces, so I take the entire roll to my machine with me. I will show you the steps on a bodice hem and a neckline. Though the steps are identical, it may be helpful for some to see it twice. If your pattern has more than 1/4″ hem allowance, you will need to trim it down to match, unless you don’t mind the extra length on a hem. On a neckline, however, this works best in place of a facing because it requires minimal adjustment, like on the Brandy Balloon Sleeve Top* I am using here. If the seam allowance is larger than 1/4″ and you don’t trim it down, the finished neckline will sit higher on the body than drafted. The same goes for if it’s banded. Also, a slight disclaimer: I had intended on doing a traditional hem on my bodice, so I finished it with my serger (which you’ll see in photos). This is not a required step for bias binding finishes, and in fact, not recommended because it does add the slightest bulk to the seam.

1. Begin by opening your single fold bias tape and folding one of the cut edges about 1/2″ (~13mm) to the wrong side. Match this up with the right side of your curved edge in the back. Position the bias tape right sides together with the edge, aligning the raw edges with one another.
2. Begin stitching on your folded edge. Backstitch and sew right into the first fold line of the bias tape.
3. Make sure you are keeping tension on the bias tape, while also keeping the edges aligned. You do not want any slack in the tape.
4. Continue sewing around your entire hem or curved edge. When you meet the folded edge where you started, sew right over it another 1/2″ (~13mm) or so.

5. Trim away your excess bias tape.
6. Press the seam allowance well toward the bias tape. Sew on the bias tape with a 3-3.5 stitch length to understitch. This will help keep the bias tape inside the bodice. Spread the seam allowance gently while sewing.
7. Your seam should look neatly joined. Start folding back along the other crease.
8. Fold bias tape to meet your seam.

9. Give the bias tape a good press to help set the stitches.
10. Fold the bias tape to the inside. This will now completely cover your seam.
11. Press again, making sure you are not creating any creases on the right side. You should see the bodice fabric a scant 1/8″ or so on the bottom when looking at the bias tape. That’s the magic of understitching 🙂
12. From the right side, stitch the edge of the bias tape closed. I recommend practicing getting the stitching width correct. While it’s easier to stitch with the bias side up so you can see the edge, you get a much neater, more professional looking finish when all topstitching is done on the right side of the garment.

Give your completed hem one more press and admire how pretty it is! Now, I’ll show you on a neckline. Again, the steps are identical, but could still be helpful. Remember the important detail about necklines is if your seam allowance is greater than 1/4″, you need to trim any seam allowance beyond that. Bias tape has only 1/4″ included in it, so anything beyond that adds more height to the neckline. (Quick calculations for you: if your pattern has 5/8″ seam allowance, trim away 3/8″. If it has 3/8″ trim away 1/8″).

1. This will start essentially the same as the hem. Begin by opening your single fold bias tape and folding one of the cut edges about 1/2″ (~13mm) to the wrong side. Match this up with the right side of your neckline in the back. Position the bias tape right sides together with the edge, aligning the raw edges with one another.
2. Begin stitching on your folded edge. Backstitch and sew right into the first fold line of the bias tape. Make sure you are keeping tension on the bias tape, while also keeping the edges aligned. You do not want any slack in the tape.
3. Continue sewing around your entire neckline. When you meet the folded edge where you started, overlap the bias tape and sew right over it another 1/2″ (~13mm) or so.
4. Trim away the excess and it will look like this.

5. Press the seam allowance well toward the bias tape.
6. Sew on the bias tape with a 3-3.5 stitch length to understitch. This will help keep the bias tape inside the bodice. Spread the seam allowance gently while sewing.
7. Your seam should look neatly joined. Ordinarily, you clip into the curves of necklines to help them lie flat. Because this is such a narrow seam allowance, you can choose to skip it, if you want.
8. Fold bias tape to meet your seam.

9. Fold the bias tape to the inside. This will now completely cover your seam. Give the neckline a good press to help set the stitches. This is a great time to use a tailors ham to really help you keep that neckline integrity and prevent creasing from pressing.
10. Your neckline should look clean. You should see the bodice fabric a scant 1/8″ or so around the top edges when looking at the bias tape. That’s the magic of understitching 🙂
11. From the right side, stitch the edge of the bias tape closed. I recommend practicing getting the stitching width correct. While it’s easier to stitch with the bias side up so you can see the edge, you get a much neater, more professional looking finish when all topstitching is done on the right side of the garment. It’s also easier to manage the slight ease needed for such a curved edge and helps reduce incidence of puckering.
12. Press again and look at your pretty neckline!

I used this same technique to finish a full circle skirt made in African wax fabric and it’s such a glorious finish and a pretty little surprise on the inside. Anyone who’s hemmed a full circle, especially in a fabric that isn’t super pliable knows how frustrating the hemming part can be. Bias tape for the win!

I hope you found this post very helpful and that the next time you’re about to give up on curved hems, you use this as a reference. I’m always here for questions and love when readers leave comments or send me emails. Until next time!!

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