Bias tape: single-fold, double-fold and how to sew it

Single-fold, double-fold and quilt binding

The fold decides the job. If you remember nothing else: single-fold faces or becomes double-fold; double-fold wraps a raw edge from both sides; extra-wide is double-fold for batting and bags.

• Single-fold

  Cut: Cut on the bias, both long edges folded to the centre and pressed. The folds meet; they do not wrap a second time.

  Use it for: Facing a neckline or armhole from the inside, casings, decorative surface strips, and any edge you will cover with another layer. Also the starting point if you want to press it into double-fold yourself.

  Skip it for: Binding a raw edge that will be seen from both sides. Single-fold leaves one raw edge unless you hide it in a seam or facing.

• Double-fold

  Cut: Single-fold tape folded in half again, slightly off-centre so one lip is a hair wider. That wider lip goes on the back so the front stitching catches it.

  Use it for: The default for binding a raw edge: necklines, armholes, quilt bindings sold as “quilt binding,” baby clothes, bags, anything that needs a clean wrap from both sides.

  Skip it for: Very bulky cloth (canvas, coated, heavy denim) where four layers of tape plus the garment make a ridge. Cut your own extra-wide tape, or bind with a facing instead.

• Extra-wide / quilt binding

  Cut: Double-fold cut wider: often ½ in finished on each face, from a 2¼–2½ in starting strip. Sold by the pack or by the metre.

  Use it for: Quilt edges, heavier garments, bags. The extra width covers batting loft and gives you something to hold while you stitch.

  Skip it for: Fine lawn or voile necklines: the binding will overpower the cloth.

• Quilt binding cut on the straight grain

  Cut: Strips cut selvage-to-selvage, not on the true bias. Common for quilt edges that are mostly straight.

  Use it for: Square quilt edges with gentle corners. Uses less yardage than true bias and stays stable.

  Skip it for: Curved garment edges. Straight-grain binding will pucker or stretch unevenly around a neckline. Curves want true bias.

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

Widths and starting strips

Packs are labelled by the finished visible width or by the unfolded starting strip: read the package. When you cut your own, start from the unfolded strip width in the middle column.

A quick default: ⅜ in double-fold for adult necklines, ¼ in for baby clothes and lawn, extra-wide for quilts. Buy the width the pattern names when it names one: designers ease openings around a specific binding.

Making bias tape from yardage

Ready-made tape is faster. Cutting your own is how you match a print, use leftover quilting cotton, or get a length that is not sold in a pack. Fat quarters → yield enough narrow tape for a neckline; a long quilt binding wants continuous quilting cotton or another stable woven from colorful wovens.

1. Find the true bias. Fold a selvage to a cut edge so the fold sits at 45 degrees. Press the fold lightly and cut along it: that is your first bias edge.
2. Cut strips the starting width. Use a ruler and rotary cutter for even strips. 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 ¼ in seam across the diamond, trim to ¼ in, press open. Joining on the bias makes a weak, stretchy seam that shows.
4. Press the folds. A bias-tape maker feeds the strip and sets both lips; a steam iron and a pin in the ironing board will do the same more slowly. For double-fold, fold in half slightly off-centre after the first press.

How to sew it on

The method that puckers least: sew the narrower lip to the right side first, then fold to the back. “Sandwich and stitch once” is faster and less accurate: fine for a craft pouch, not for a jewel neckline.

Binding a neckline with double-fold, step by step

1. Staystitch. A line of stitching just inside the seam keeps the garment bias from growing while you handle it.
2. Join or leave tails. Closed opening: join the tape into a loop, matching the join to a shoulder seam. Open edge: leave 2 cm tails to turn under at each end.
3. Sew the narrower lip. Open the tape. Pin the narrower fold to the right side, raw edges even. Stitch in the crease, easing: never stretching: around the curve.
4. Fold and catch the back. Bring the wider lip over the raw edge. Stitch in the ditch from the front, or slipstitch by hand if you do not want a line of machine stitching on the face.
5. Steam into shape. Press over a ham or the end of the board so the curve sets. If it ripples, you stretched the tape; 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. The fold becomes the mitred corner on both faces. Join the last ends with a diagonal seam so the join sits as flat as the rest of the binding.

Needle: universal 70/10 or 80/12 on cotton tape. Thread from the sewing thread shelf: match or contrast on purpose. Needle types → if the point is skipping.

Which tape for which project

• Sleeveless dress or tank: ⅜ in double-fold around neck and armholes. Pair with lawn, voile or a stable woven — sewing dresses with natural fibers →.
• Baby bib or burp cloth: ¼ in double-fold, joined into a loop. Soft cotton tape, not stiff polyester.
• Quilt: extra-wide double-fold or straight-grain binding cut 2¼ in from yardage. Fat-quarter leftovers work for a small throw; a bed quilt wants a continuous cut.
• Bag opening: ½ in double-fold, or a facing plus interfacing → if the mouth needs to stand.
• Decorative surface strip: single-fold, topstitched along both lips. Not a substitute for a structural seam.

Quick answers

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

Single-fold has the two long edges folded to the centre; one face is still open. Double-fold is that tape folded in half again so it wraps a raw edge from both sides. Use single-fold as a facing or to make your own double-fold. Use double-fold to bind.

Do I have to cut bias tape on the bias?

For curves, yes: the 45-degree grain is what lets the tape ease around a neckline without puckering. Straight quilt edges can take straight-grain binding. If a ready-made pack does not say “bias,” assume it is bias only if the package names it.

How much bias tape do I need?

Measure the edge, add 10–15 cm for joining and turning corners, and buy a little extra if the colour has to match later. A jewel neckline is often 50–60 cm; a quilt perimeter is the four sides plus 20–25 cm for the join.

Can I make bias tape from fabric I already have?

Yes, and it is usually the better colour match. Cut 45-degree strips, join them on the straight grain, and press with a bias-tape maker or a steam iron and a pin. One fat quarter yields several metres of narrow tape; continuous yardage is smarter for a long quilt binding.

Why does my bias binding twist or ripple?

Usually the tape was stretched as it was sewn, or it was applied to a curve that wanted more ease. Staystitch the garment edge first, sew the narrower lip to the right side without pulling, then fold to the back and stitch in the ditch or by hand. Steam, do not yank.

What needle and stitch should I use on bias tape?

A universal 70/10 or 80/12 on woven cotton tape; a microtex on dense or coated cloth. A short straight stitch (2–2.5 mm) for woven bindings; a narrow zigzag if the garment itself is a knit. Polyester or cotton all-purpose thread in a matching or deliberately contrasting colour.