Sewing bias tape is a way to finish raw fabric edges with a neat, flexible binding

Bias tape is a strip of fabric cut at a 45-degree angle to the grain, which makes it stretch and curve smoothly around corners and curves. When you sew it to an edge, it wraps around and binds the raw threads so they don't fray. The tape comes pre-folded in most cases—one long edge is folded inward already—so you only have to fold it once more as you sew.

The basic method is to pin the tape to the right side of your fabric, sew it down with a straight stitch, then fold the tape to the back and stitch it in place by hand or machine. The whole process takes about 15 to 20 minutes for a straightforward edge like an armhole or neckline, depending on the length.

Key Takeaways

  • Pre-folded bias tape has one fold already pressed in; you unfold one side, pin it to the right side of your fabric, and sew along the crease line.
  • The tape must be pinned smoothly without puckers, especially around curves—ease it gently as you pin rather than stretching it.
  • After the first seam, fold the tape to the back of the fabric and stitch it down by hand with a ladder stitch or by machine along the fold line.
  • Common mistakes include sewing too close to the edge (the tape won't wrap around), pinning too tight on curves, and not pressing the final fold before stitching.

What you need before you start

Gather pre-folded bias tape in a width that matches your project—typically 1/2 inch or 1 inch wide. You will also need a sewing machine with a straight-stitch needle, thread that matches the tape or fabric, pins, an iron, and scissors. A seam ripper is useful if you need to undo a seam, and a pressing ham or rolled towel helps you press curves without flattening them.

Measure the edge you plan to bind. If you are binding an armhole or neckline, measure around the opening with a soft measuring tape. Buy tape that is at least 2 inches longer than your measurement so you have room to overlap the ends. If you are binding a straight edge like a quilt border, measure the length and add 1 inch.

Preparing the fabric edge and tape

Trim any loose threads from the edge you plan to bind. If the edge is a raw seam allowance, trim it to about 1/4 inch wide so it fits neatly inside the tape. Press the edge flat with an iron so it lies smooth—a wavy edge will pucker when you pin the tape.

Unfold one long side of the pre-folded bias tape. You will see two creases: one where the tape was originally folded, and one where you just unfolded it. The unfolded edge is what you will pin to the fabric. Press the tape flat with an iron if it has curled or twisted in storage.

Pinning the tape to the right side of the fabric

Place the fabric right-side up on your work surface. Unfold the bias tape and lay it flat, unfolded side down, along the edge of the fabric. The raw edge of the tape should line up with the raw edge of the fabric. Start at a straight section, not at a corner or curve.

Pin the tape every 2 to 3 inches, pushing the pin straight through both the tape and fabric. On curves, pin more often—every 1 inch—and ease the tape gently as you pin. Do not stretch the tape; instead, let it bunch slightly on the fabric so it will curve smoothly when you sew. On inside curves (like a neckline), the tape will naturally bunch. On outside curves (like an armhole), you may need to clip small notches into the tape's seam allowance so it spreads without puckering.

When you reach a corner, fold the tape at a 45-degree angle, then fold it back along the next edge. This creates a mitered corner. Pin both sides of the corner so the tape lies flat.

Sewing the tape to the fabric

Thread your machine with thread that matches the tape or blends with the fabric. Set the machine to a straight stitch with a stitch length of 2.0 to 2.5 millimeters. Sew along the crease line where you unfolded the tape—this line is your guide. Sew slowly, especially around curves, and remove pins as you approach them rather than sewing over them.

Start sewing about 1 inch from the beginning of the tape. When you reach the end, overlap the tape by about 1 inch and sew past the starting point. Trim the overlap to 1/2 inch, then fold both raw ends inward and stitch them closed by hand or machine.

Press the seam flat with an iron. This sets the stitches and makes the next step easier.

Folding and stitching the tape to the back

Fold the tape to the back of the fabric so it wraps around the edge. The fold line of the tape (the crease that was already there) should sit right at the seam you just sewed. Press this fold with an iron, working in small sections. On curves, use a pressing ham or rolled towel underneath so you don't flatten the shape.

You now have two choices: stitch the tape by hand or by machine. Hand stitching is slower but gives a nearly invisible finish. Use a ladder stitch (also called an invisible stitch), catching only a few threads of the fabric and the fold of the tape, and space your stitches about 1/4 inch apart. Machine stitching is faster and holds up well in washing. Sew from the front of the fabric along the original seam line, which will catch the folded tape on the back.

If you machine stitch, use a thread color that matches the tape so the stitches are less visible from the front. Sew slowly and check the back occasionally to make sure the tape fold is staying in the seam line.

Finishing and pressing the bound edge

Once the tape is stitched on both sides, press the entire bound edge with an iron. Use a pressing cloth (a thin cotton cloth) between the iron and the tape to avoid shine. Press from the back first, then from the front, using a gentle up-and-down motion rather than sliding the iron, which can stretch the tape.

Trim any loose threads with scissors. If you see any gaps where the tape did not catch the fabric, go back and hand stitch those spots closed. A well-finished edge should look the same width all the way around, with no puckers or loose spots.

Frequently Asked Questions

Can I use single-fold bias tape instead of pre-folded?

Yes, but it takes longer. Single-fold tape has only one crease down the middle. You unfold it completely, pin it to the fabric, sew it, then fold both sides to the back and stitch. Pre-folded tape saves this step because one fold is already done. Either type works; pre-folded is just faster for beginners.

What do I do if the tape puckers while I'm sewing?

Stop and remove the stitches back to where the pucker started. Unpin that section, smooth the tape and fabric, and re-pin more loosely. Puckers usually mean the tape was pinned too tight or stretched. Ease it gently instead of pulling it taut.

How do I bind a corner neatly?

At a corner, fold the tape at a 45-degree angle, then fold it back along the next edge so it forms a diagonal line at the corner. Pin both sides of the corner and sew through all layers. When you fold the tape to the back, the corner will form a neat miter. This takes practice, but the angle guides the tape naturally.

Should I use a walking foot for bias tape?

A walking foot helps prevent the tape and fabric from shifting, especially on curves and stretchy fabrics. It is not required, but it makes the seam straighter and more even. If you do not have one, sew slowly and hold the tape and fabric gently as you feed them under the presser foot.

Can I sew bias tape on a knit or stretchy fabric?

Yes, bias tape is ideal for knits because it stretches with the fabric. Use a ballpoint needle instead of a sharp needle to avoid snagging the fibers. You may also want to use a walking foot or a stretch needle to keep the seam from puckering. Sew slowly and do not pull the fabric as you sew.