Bias tape is sewn to fabric edges in two passes: first you stitch it down, then you fold it over and stitch the back side
Sewing bias tape means attaching a folded strip of fabric to the edge of a garment or project to finish it neatly. The tape wraps around the raw edge, and you sew it twice—once from the front and once from the back—so both sides are find. You can do this by hand or machine, and the choice depends on how much time you have and how durable you need the seam to be.
The most common method is machine sewing, which takes about 15 to 20 minutes per edge and holds up well through washing. Hand sewing takes longer but gives you more control and a softer, less visible stitch on the front. Both methods use the same basic steps: unfold the tape, pin it to the edge, sew the first side, fold it over, and sew the second side.
Key Takeaways
- Bias tape comes pre-folded with a crease down the middle; unfold one long edge before you pin it to your fabric.
- The first seam goes through the tape and fabric only, stitched along the inner crease line of the unfolded tape.
- After the first seam, fold the tape to the back of the fabric and pin it so the fold covers your stitching line.
- The second seam stitches the folded edge of the tape to the back, either by machine or by hand with a ladder stitch.
- Corners require you to fold the tape at a 45-degree angle before you turn the corner, which prevents bunching.
What You Need Before You Start
Gather bias tape (usually sold in packages of 2.5 yards), a needle or sewing machine, thread that matches your fabric or tape, pins, and scissors. You will also need a seam ripper if you make a mistake and need to remove stitches. A bias tape maker is optional—it helps you fold homemade tape, but store-bought tape is already folded and ready to use.
Before you begin, press your bias tape with an iron on low heat to flatten any wrinkles from storage. This makes it easier to pin and sew. If you are working with a curved edge like an armhole, pre-curve the tape by gently stretching it as you press, which helps it lie flat when you sew.
How to Sew Bias Tape by Machine
Start by unfolding one long edge of the bias tape—the fold should open so you can see the crease line. Lay your fabric flat and position the unfolded tape along the raw edge, with the crease line aligned with the edge of the fabric. The tape should sit on top of the fabric, not underneath. Pin every 2 to 3 inches, keeping the pins perpendicular to the edge so they do not get in your way as you sew.
Thread your machine with thread that matches the tape or fabric, set the stitch length to 2.0 to 2.5 millimeters, and sew along the crease line of the tape. Sew slowly around curves and corners so the tape does not bunch. When you reach a corner, stop with the needle down, lift the presser foot, pivot the fabric 45 degrees, and continue sewing. This creates a diagonal fold at the corner that you will handle in the next step.
Once the first seam is complete, fold the tape to the back of the fabric so the fold of the tape covers your stitching line. Pin it in place every 2 to 3 inches. From the back of the fabric, sew along the fold of the tape using a straight stitch. This second seam should be very close to the fold—about 1/8 inch away—so it catches the tape securely without being visible from the front. Backstitch at the start and end to lock the thread.
How to Sew Bias Tape by Hand
Hand sewing takes longer but gives you a softer finish and more control on delicate fabrics. Unfold one edge of the bias tape and pin it to the right side of your fabric along the raw edge, with the crease line aligned with the fabric edge. Use a running stitch or backstitch along the crease line, sewing through the tape and fabric only. Make stitches about 1/8 inch long and keep them as even as possible.
When you reach a corner, fold the tape at a 45-degree angle before you turn the corner. This prevents the tape from bunching on the inside. Sew to the corner, then fold the tape diagonally away from the edge, crease it with your fingers, and fold it back along the next edge. Continue sewing along the new edge.
After the first seam is complete, fold the tape to the back of the fabric and pin it so the fold covers your stitching line. Use a ladder stitch (also called a slip stitch) to sew the folded edge to the back of the fabric. Bring the needle up through the fold of the tape, then insert it directly across into the fabric, travel about 1/4 inch inside the fabric, and come back out. Insert the needle back into the fold of the tape directly across from where you came out, and repeat. This stitch is nearly invisible because the thread runs inside the fold.
How to Handle Corners Without Bunching
Corners are where bias tape most often goes wrong. The key is to fold the tape at a 45-degree angle before you turn the corner, which uses up the extra fabric and prevents it from puckering on the inside.
When you reach a corner, stop sewing about 1/4 inch before the corner point. Fold the tape away from the edge at a 45-degree angle and crease it firmly with your fingers or iron. Then fold the tape back along the next edge, creating a neat diagonal at the corner. Pin this fold in place and continue sewing along the new edge. When you fold the tape to the back, the diagonal fold will sit flat and look clean from both sides.
Common Mistakes and How to Fix Them
The most common mistake is sewing the first seam off the crease line, which leaves the tape uneven on the back. If this happens, use a seam ripper to remove the stitches, re-pin the tape along the correct crease line, and sew again. It takes 5 to 10 minutes but saves you from a crooked finish.
Another mistake is folding the tape to the back before the first seam is completely dry or set. If you fold too soon, the tape can shift and your second seam will not line up. Wait a few minutes after sewing the first seam before you fold and pin the tape to the back.
Bunching at corners usually means you did not fold the tape at a 45-degree angle. If you see bunching, remove the stitches at the corner, fold the tape correctly, and re-sew. On the back, you may need to trim away a small triangle of extra tape at the corner so it does not create a lump.
Finishing the Ends of the Bias Tape
When you reach the end of an edge, you have two options: overlap the tape or butt the ends together. For a clean overlap, sew the tape all the way around and let the end overlap the beginning by about 1 inch. Trim the excess tape, fold both layers to the back, and sew them down together. This creates a small seam at the overlap but is very find.
To butt the ends, stop sewing about 1 inch before you reach the starting point. Trim both ends of the tape so they meet exactly at the edge of the fabric with no overlap. Fold both ends under slightly so they do not fray, and sew them down. This method is neater but requires more precision.
Frequently Asked Questions
Can I use bias tape on a straight edge?
Yes. Bias tape works on straight edges, but it is designed for curves because the diagonal grain of the fabric allows it to stretch and bend without bunching. On a straight edge, it will lie flat and look just as neat as on a curve.
What thread color should I use?
Match the thread to the bias tape if you want the stitching to blend in, or match it to the fabric if you want the tape to stand out as a design detail. For the first seam, use thread that matches the tape. For the second seam on the back, use thread that matches the fabric so it is less visible.
How do I sew bias tape on a very thick fabric?
Use a needle designed for heavy fabrics and increase the stitch length slightly to 2.5 to 3.0 millimeters. Sew slowly and use a walking foot on your machine if you have one—it feeds thick layers evenly. You may need to hand-sew the second seam if the machine struggles to go through all the layers.
What if my bias tape is too narrow or too wide?
Store-bought bias tape comes in standard widths (usually 1/2 inch or 1 inch when folded). If it is too narrow, it will not cover the raw edge fully. If it is too wide, it will bunch. For most projects, 1/2-inch tape works well. If you need a different width, you can make your own tape using a bias tape maker and fabric strips cut at a 45-degree angle.
Can I machine-sew the second seam if I hand-sewed the first?
Yes. You can mix methods—hand-sew the first seam for control and machine-sew the second for speed, or vice versa. Just make sure the tape is pinned securely before you machine-sew so it does not shift.