The corner is where bias tape either lies flat or wrinkles
Sewing bias tape around a corner comes down to one thing: you have to fold the tape at a 45-degree angle before you stitch past the corner point. If you keep the tape flat and try to turn it, it will bunch on the inside of the curve and pucker on the outside. The fold creates slack in the tape so it can bend without distorting the fabric underneath.
The method works the same whether you are binding the edge of a quilt, finishing an armhole on a garment, or edging a curved neckline. The corner itself—whether it is a right angle or a gentler curve—determines how much tape you fold, but the principle stays constant.
Key Takeaways
- Stop stitching exactly at the corner point, then fold the bias tape at a 45-degree angle before you resume sewing on the next side.
- The fold creates a small triangle of tape at the corner that will be hidden when you fold the tape to the back and stitch it down.
- Use a seam ripper to open the fold of the bias tape at the corner so you can see exactly where to stitch.
- Press the corner fold with an iron before you stitch it to keep the tape from shifting while you sew.
Stop at the corner point, not past it
The first step is knowing exactly where to stop stitching. Measure or mark the corner point on your fabric before you begin. If you are binding a quilt square, the corner is where the two edges meet at a right angle. If you are finishing a neckline, the corner is the lowest point of the curve or the sharpest angle.
Stitch the bias tape along the first edge and stop when your needle reaches that corner point. Backstitch to lock the thread, then remove the fabric from the machine. Do not stitch past the corner—stopping at the exact point is what gives you room to fold the tape without creating bulk.
Fold the tape at 45 degrees and press it
With the fabric still out of the machine, fold the bias tape up and away from the fabric at a 45-degree angle. The fold should point outward from the corner. If you are working on a right-angle corner (like a quilt), the fold will create a small triangle of tape that sticks out beyond the fabric edge.
Once you have made the fold, press it with an iron on medium heat. This holds the fold in place and prevents the tape from shifting when you resume stitching. Let it cool for a few seconds before you touch it.
If you are working on a curved edge, the fold will be gentler and less obvious, but the principle is the same: you are creating slack in the tape so it can follow the curve without bunching.
Fold the tape down along the second edge
After the 45-degree fold is pressed, fold the tape down so it lies flat along the next edge of your fabric. The tape should now run along the second side of the corner, and the 45-degree fold you just made will be hidden underneath. Press this fold as well to keep it crisp.
At a right-angle corner, this fold creates a neat mitered corner—the kind you see on professionally bound quilts. The small triangle of tape at the corner is now sandwiched between the fabric and the bias tape, so it will not be visible when the binding is complete.
Stitch from the fold line, not from the edge
Put the fabric back in the machine and position your needle so it starts stitching from the fold line you just created, not from the very edge of the fabric. This is the key detail that many people miss. If you stitch from the edge, you will catch the 45-degree fold and create a lump.
Stitch along the second edge using the same seam allowance you used on the first edge (usually 1/4 inch for quilting, or whatever your pattern calls for). When you reach the next corner, repeat the process: stop at the corner point, fold at 45 degrees, press, fold down, and resume stitching.
Use a seam ripper to see the fold line clearly
If you are having trouble seeing where the fold line is, use a seam ripper to gently open the fold of the bias tape at the corner. This lets you see the crease clearly and position your needle exactly where it needs to be. You do not have to rip any stitches—just open the fold enough to see the line.
This is especially helpful on curved corners or when you are working with thick fabric or multiple layers. Once you can see the fold line, close the fold back up, press it again, and stitch.
Finish the back side the same way you normally would
After you have stitched the bias tape all the way around and back to where you started, fold the tape to the back of the fabric and stitch it down by hand or machine, just as you would on a straight edge. The corners will lie flat because you created the slack with the 45-degree folds.
If you are machine-stitching the back, stitch in the ditch (the groove created by the seam) so your stitches are hidden. The corner folds will stay in place and the binding will look professional and flat.
Frequently Asked Questions
What if I stitch past the corner by accident?
Use a seam ripper to remove the stitches back to the corner point, then fold and press the tape as described. It is easier to fix this before you fold the tape down than after. If you have already folded and stitched, you can still open it up and redo that section—the fabric will not be damaged.
Do I need to fold the tape at every corner?
Yes, every corner needs a fold to prevent bunching and puckering. Even gentle curves need a small fold. The sharper the corner, the more obvious the fold will be, but the technique is the same.
Can I use this method on curved edges like armholes?
Yes. On a curve, you will make many small folds instead of one large fold at a corner point. Stop every inch or so, fold the tape at a shallow angle, press, and resume stitching. This keeps the tape from bunching as it follows the curve.
What seam allowance should I use at the corner?
Use the same seam allowance you used on the straight edges. If your pattern calls for 1/4 inch, use 1/4 inch at the corner too. The fold you create will sit within that seam allowance and will not be visible.