In this tutorial I’ll show you how to finish a neckline with bias tape. We’ll be walking through Step 2 of the Onyx Shirt instructions, but you can follow these steps for any curved seam finished with bias tape. Before I used the techniques shown here, it took me quite a few tries to get this right. I always felt like tutorials made it seem so easy. And yet I could not get the neckline to lay flat, there were wrinkles, just not something I could really be proud of. But I’ve developed/discovered a few tricks that now give me the results I want, and I hope that after this tutorial you can be proud of your bias tape necklines too!
Bias tape or binding can be used as a finishing method to enclose the raw edge of a neckline. The key to sewing a bias tape neckline is using the right kind of bias tape, pressing after each step, understitching, and shaping the bias tape to the neckline curve with your fingers.
Before you start
Lets start with a few general tips. First you should consider the kind of fabric your tape is made of in relation to your top. Store bought bias tape can be quite stiff. This is no problem when you’re using a medium weight fabric. When you’re using lightweight fabrics it’s easier to either use a lightweight bias tape or to make your own bias tape. If you make bias tape from the same fabric you’re using for your top you get the best results. A great tutorial for making your own bias tape is this one from Colette.
I made my own tape for the Onyx product samples. For this tutorial I made it difficult for myself and used a medium weight tape for a lightweight fabric. Just to show you that even then you can get a flat, wrinkle free neckline!
Second, in the Onyx instructions we recommend using 3/8″ (1 cm) single fold bias tape. The narrower the bias tape, the easier it is to get a flat neckline. If you only have double fold bias tape, just cut a strip off so you get the required width. That’s what I did for this tutorial, too.
What you need
- Your Onyx shirt, sewn up to Step 2
- 75-80 cm of bias tape, depending on the neckline
- sewing machine
Step 1: First seam
Open up one side of the bias tape and press it flat. Position the tape on the right side of the fabric, at the center back of the neckline (indicated by the pen mark), so that the crease of the opened side is a 3/8″ (1 cm) from the raw edge. Pin the tape 1″ toward the shoulder seam. Leave a tail of 1″ past the center back.
Start sewing in the crease of the tape 1″ from the center back. Sew around the neckline until 1″ from the center back. I find it easiest not to pin the tape in advance, but to position it as I sew. Be careful not to stretch the fabric, let the tape follow the curve of the neckline.
Bring the two tails together at the center back. To find the place where they should meet, fold one double. Fold the other one against it in the opposite direction. Then match and sew the folds together.
Open up the tails and press. Trim the excess tape. Sew the remaining 2″ of tape to the back neckline.
Step 2: Understitching
Understitching is a line of straight stitching sewn just beyond the seam line of two pieces that have been sewn together. One of the pieces is the seam allowance of your garment (in this case the fabric), the other is what will be on the inside (the bias tape). In order to keep the neckline edge sharp and clean, you understitch the bias tape to the seam allowance so it won’t roll to the outside.
Press the bias tape up, away from the bodice. You don’t need to press the tape flat – just press the edge of the tape with the tip of your iron. Stitch through the tape and the seam allowance of the bodice, as close to the pressed edge as you can. Trim the seam allowance of the garment close to the understitching.
Turn the shirt inside out and fold the bias tape out along the neckline curve. Press the bias tape along the curve, so no tape is visible on the right side of the garment. The under stitching ensures that the edges roll nicely to the outside, so the tape isn’t visible from the right side.
Step 3: Shaping
What you’ve done by attaching the bias tape, is sewn a straight piece of fabric (the tape) to a curved one (the neckline). No wonder it doesn’t lay flat nicely, right? So what we’ll do next is shape the tape into a curve. This is what makes the difference between a flat bias neckline and one that stands away from the body.
By stretching the outer edge of the bias tape you shape it to match the neckline curves. In the images above you can see the difference this makes. The video below shows how I shape the bias tape.
You hold the tape between your fingers, and move your palms toward each other. This stretches the outer edge but not the seam. You can do this lightly at the straight parts like the back neckline, and stretch it more at curved parts, like the shoulders and the curved front of the neckline.
Step 4: final seam
Give the neckline a good press. Sew the tape to the neckline. Keep the fabric underneath taut to prevent wrinkles. Follow the curve of the neckline.
Give the neckline a final press. This one eliminates the last wrinkles, as shown by the difference in the images above. The second one has only some slight wrinkling and lies flat against the body.
It’s a bit of a fiddly process and even with the best tutorial it requires some practice. The Love To Sew podcast has a fun episode all about bias tape if you’d like to know more. If you have any questions, leave a comment below.