How To Sew A Continuous Bias Binding

Continuous bias binding is a useful way to turn one square of woven fabric into a long, uninterrupted strip. The method avoids lots of separate joins, keeps the grain running correctly around curves, and makes excellent use of fabric leftovers.

Bias tape is cut diagonally across the grain, giving it gentle stretch and flexibility. That movement allows it to sit smoothly around necklines, armholes, hems, pockets, and other curved edges. Once the basic arrangement makes sense, making your own binding becomes a quick and satisfying part of garment sewing.

The finished tape can be single-fold or double-fold, narrow or wide, plain or decorative. It is particularly handy when a pattern calls for handmade binding or when you want the inside of a garment to coordinate with the outer fabric.

What Bias Grain Does

Woven fabric has lengthwise and crosswise grainlines, both of which are relatively stable. The bias lies at approximately 45 degrees to those threads. Cutting along this diagonal gives the fabric enough flexibility to mould around curves without creating bulky gathers or sharp points.

For most garment edges, a strip between 1½ and 2 inches wide is a practical starting point. Narrower binding works well for delicate armholes and fine fabrics, while wider strips are easier to handle when you are learning or working with a heavier material.

Bias binding should be cut from a stable woven fabric rather than a stretch knit. Cotton lawn, quilting cotton, linen, lightweight denim, and many dressmaking wovens are suitable. Avoid fabrics that fray excessively unless you are prepared to stabilise the edges during construction.

Prepare Fabric And Tools

Begin with a square of fabric. The larger the square, the longer the continuous strip will be. A 20-inch square can produce a useful amount of binding, while a fat quarter may be enough for a neckline or small facing project. Press the fabric first, then trim away uneven edges so the square is accurate.

You will need a fabric marker or chalk, a ruler, fabric scissors or a rotary cutter, a cutting mat, pins or clips, and an iron. A rotary cutter makes the long diagonal cuts especially clean, but sharp dressmaking scissors work perfectly well.

If you are using small remnants, there is another approach worth exploring in this guide to scrap-fabric bias tape. Whichever method you choose, match fabrics with similar weights so the finished binding behaves consistently.

Create The Continuous Strip

Fold the square from one corner to the opposite corner and cut along the fold or marked diagonal. You will now have two triangular pieces. Rearrange them so the short straight edges meet and the pieces form a long parallelogram. The diagonal cut edges should run parallel to each other.

Sew the two short edges together with a narrow seam. Press the seam open, or press it towards one side if the fabric is very light. Trim any little points that extend beyond the long edges. You should now have a joined shape with two long bias edges and two shorter ends.

Next, use a ruler to mark parallel lines across the shape. The distance between each line should equal the required finished strip width before folding. For example, mark 2-inch intervals for binding that will eventually be folded into a narrower double-fold tape.

The key is to mark the lines continuously from one long edge to the other. When you reach the far end, stop before cutting. Bring the two short ends together to form a loose tube, then shift them so the marked lines meet in a stepped arrangement. Pin or clip the edges together, checking that each line leads naturally into the next one.

Sew this final seam carefully. It may look unusual because the fabric forms a slightly twisted tube, but that offset is what creates one continuous spiral. Starting at one edge, cut along the marked line and keep following it around the tube. Do not cut across the final uncut section until you have checked that the strip is connected throughout.

Select The Right Binding Width

The cutting width depends on how the binding will be applied. Single-fold binding is pressed in half along its length and usually attached with one raw edge aligned to the garment edge. Double-fold binding is folded in stages so that the raw edges are enclosed, making it a neat choice for visible necklines and armholes.

Use	Suggested Cut Width	Useful Finish
Small armhole or delicate edge	1¼–1½ inches	Narrow single or double fold
General neckline binding	1½–2 inches	Double fold
Hem or feature trim	2–2½ inches	Wide single fold
Heavy fabric or bulky seam	2½ inches or more	Pressed, applied binding

After cutting, join any remaining tiny gaps with a diagonal seam rather than a straight one. A diagonal join spreads the bulk across the strip and is less visible once the tape is folded. Press every join open, then run the complete strip through a bias tape maker if you have one.

Without a tape maker, press the strip in half with wrong sides together for single-fold binding. For double-fold binding, press both long raw edges towards the centre, then fold the strip in half again. Work in short sections and use plenty of steam, taking care not to stretch the bias as you press.

Attach Binding Without Ripples

Before sewing, stabilise the garment edge if the pattern recommends it. Stay-stitching just inside the seam allowance can prevent a neckline from growing, especially on loosely woven fabric. Measure the edge rather than assuming the binding length will match the paper pattern.

Attach the binding with the right sides together, matching one raw edge of the tape to the garment edge. Ease the binding around curves without pulling it. On an inward curve, the garment edge may need slight easing; on an outward curve, small clips in the seam allowance can help the binding spread.

Sew with the binding underneath if your machine feeds that layer more smoothly. Keep the seam allowance even, and pause with the needle down when adjusting a curve. When the first pass is complete, understitch the binding where appropriate, then press it away from the garment before folding it to the inside.

A well-fitting neckline makes this finishing step much easier. If you are binding a curved top, the Sloane fitting tips offer useful reminders about checking shape and balance before adding the final finish.

Solve Common Binding Problems

If the strip twists while you cut, the offset seam was probably pinned with the marked lines misaligned. Unpick the joining seam and lay the tube flat again, matching each line to the next. The strip should emerge as one continuous path rather than separate loops.

Wavy binding usually comes from stretching the tape while pressing or sewing. Steam can relax the fibres, but do not drag the iron along the strip. Let it cool flat before attaching it. If the garment edge is stretched, remove the stitching, stabilise the edge, and try again with a slightly shorter binding length.

Uneven width is often caused by inaccurate marking or a shifting ruler. Mark from one long edge with a dependable quilting ruler, and rotate the fabric rather than reaching across it. Small variations may disappear inside a seam allowance, but significant changes will make folding and topstitching difficult.

Keep The Process Reliable

A few consistent habits make homemade bias tape easier to cut, press, and apply. Test the width and folding method on a short sample before cutting a valuable fabric square. This also lets you check whether the weight and colour suit the garment.

Keep the iron close by throughout the process. Pressing the joined seams, setting the folds, and shaping the binding around a curve will produce a noticeably cleaner result than trying to correct everything at the end.

• Use a sharp blade or scissors so the bias edges stay smooth.
• Mark the strip width accurately before joining the tube.
• Press seams and folds without stretching the fabric.
• Match the binding weight to the garment fabric.
• Sew a small practice curve before working on the finished piece.

Continuous bias binding turns an ordinary fabric square into a versatile sewing resource. Once the parallelogram and offset tube have been mastered, the cutting process becomes straightforward, and the resulting tape can give handmade garments a polished finish. Save this method for your next neckline, armhole, or bound hem, then browse Josie’s sewing projects for more practical techniques and pattern inspiration.