Bias Tape: Single-Fold, Double-Fold, and How to Sew It

Single-fold, double-fold, and quilt binding

• Single-fold

  Both long edges folded to the center and pressed. Use it to face a neckline or armhole from the inside, for casings, and as the starting point if you want to press it into double-fold yourself. Skip it when a raw edge will be seen from both sides.

• Double-fold

  Single-fold tape folded in half again, slightly off-center so one lip is a hair wider. The wider lip goes on the back so the front stitching catches it. This is the default for binding a raw edge: necklines, armholes, baby clothes, bags. Skip it on very bulky fabric, where four layers of tape plus the garment make a ridge.

• Extra-wide or quilt binding

  Double-fold cut wider. Often 1/2 in finished on each face, from a 2 1/4 to 2 1/2 in starting strip. Use it for quilt edges, heavier garments, and bags. Skip it on fine lawn or voile necklines.

• Quilt binding cut on the straight grain

  Strips cut selvage to selvage. Use it for square quilt edges with gentle corners. Skip it on curved garment edges. Curves need true bias.

Shop bias tape: single-fold, double-fold, and extra-wide, or the neighboring binding basket. Decorative edges that are not bias live with ric rac and trims →.

Widths

Read the package. Packs are labeled by finished visible width or by the unfolded starting strip.

We recommend 3/8 in double-fold for adult necklines, 1/4 in for baby clothes and lawn, and extra-wide for quilts. Buy the width the pattern names when it names one.

Making bias tape from yardage

Ready-made tape is faster. Cutting your own is how you match a print or get a length that is not sold in a pack. Shop Fat quarters →, quilting cotton, and fabric.

1. Find the true bias. Fold a selvage to a cut edge so the fold sits at 45 degrees. Cut along that fold.
2. Cut strips the starting width. Use a ruler and rotary cutter. See rotary cutter sizes and blades → if you are choosing a cutter for this job.
3. Join on the straight grain. Place two strips right sides together at a right angle, stitch a 1/4 in seam across the diamond, trim, and press open. Joining on the bias makes a weak seam.
4. Press the folds. A bias-tape maker, or a steam iron and a pin, will set both lips. For double-fold, fold in half slightly off-center after the first press.

How to sew it on

Sew the narrower lip to the right side first, then fold to the back.

1. Staystitch just inside the seam so the garment edge does not grow.
2. Closed opening: join the tape into a loop and match the join to a shoulder seam. Open edge: leave 2 cm tails to turn under.
3. Open the tape. Pin the narrower fold to the right side, raw edges even. Stitch in the crease. Ease around the curve. Do not stretch.
4. Bring the wider lip over the raw edge. Stitch in the ditch from the front, or slipstitch by hand.
5. Steam into shape over a ham. If it ripples, the tape was stretched. Let more length into that section.

Quilt corners: stop a seam-width from the corner, fold the tape up at 45 degrees then back down to form a mitre, and continue.

Needle: universal 70/10 or 80/12 on cotton tape. Short straight stitch, 2 to 2.5 mm, for woven bindings. A narrow zigzag if the garment is a knit. Thread from the sewing thread basket. Needle types →

Which tape for which project

• Sleeveless dress or tank: 3/8 in double-fold around neck and armholes.
• Baby bib: 1/4 in double-fold, joined into a loop. Soft cotton tape.
• Quilt: extra-wide double-fold, or straight-grain binding cut 2 1/4 in from yardage.
• Bag opening: 1/2 in double-fold, or a facing plus interfacing → if the mouth needs to stand.
• Decorative surface strip: single-fold, topstitched along both lips.

Quick answers

What is the difference between single-fold and double-fold?

Single-fold has the two long edges folded to the center. Double-fold is that tape folded in half again so it wraps a raw edge from both sides.

Do I have to cut bias tape on the bias?

For curves, yes. Straight quilt edges can take straight-grain binding.

How much do I need?

Measure the edge, add 10 to 15 cm for joining and corners. A jewel neckline is often 50 to 60 cm. A quilt perimeter is the four sides plus 20 to 25 cm for the join.

Why does binding twist or ripple?

The tape was stretched, or the curve needed more ease. Staystitch first. Sew the narrower lip without pulling. Steam. Do not yank.