When you’re sewing, finishing techniques can transform a project from ordinary to polished. One of the most versatile tools in a sewist’s kit is bias tape. In this guide you’ll discover what is bias tape, how it works, the differences between bias tape and bias binding, and practical tips for using it across garments, accessories and home textiles. Whether you’re a complete beginner or a seasoned maker, understanding bias tape opens up a world of neat edges, curved seams and professional-looking finishes.
What is Bias Tape? Basic Definition
Bias tape is a strip of fabric cut on the bias, meaning at a 45-degree angle to the woven grain. Because of this diagonal cut, the fabric has more stretch and yield, allowing it to drape smoothly around curves, corners and irregular edges. Unlike fabric cut on the warp or weft, bias cut strips have a natural pliability that makes them ideal for finishing necklines, armholes, and hems with a clean, continuous edge.
In everyday sewing terminology, bias tape is the long strip you fold and press to create a finished boundary. The crucial idea behind what is bias tape is its bias-cut origin, which is what gives it its characteristic stretch and flexibility. That stretch is what helps it hug curves and arcs without pulling, puckering or creating stiffness at the edge.
What is Bias Tape? vs Bias Binding: What’s the Difference?
People sometimes use the terms bias tape and bias binding interchangeably, but there are subtle distinctions in practice. Bias tape refers to the strip itself, which can be used in a single fold, double fold, or with rolled edges. Bias binding describes the finished application of bias tape around an edge, often with the intention of a clean, decorative finish that sits flat against the fabric.
In short, bias tape is the material; bias binding is one common way to apply that material. For many sewing projects, you’ll purchase ready-made bias tape in various widths, or you’ll craft your own bias tape at home and apply it as bias binding to neckline edges, armholes or hems. For the purposes of this guide, we’ll cover both the creation of bias tape and its application as bias binding, so you can choose the method that best suits your project.
Types and Formats of Bias Tape
Bias tape comes in several forms, each with its own applications. Knowing the differences helps you pick the right type for your project and can save time in the workshop.
Single-Fold Bias Tape
Single-fold bias tape forms a single crease along the length. It’s typically used to bind edges when a simple, narrow finish is desired. The raw strip is folded in half lengthwise and pressed, producing a narrow finished edge that can be stitched close to the fold line. This is ideal for light to medium-weight fabrics and for delicate finishes where you want a subtle edge.
Double-Fold Bias Tape
Double-fold bias tape starts as a wider strip that is folded in half lengthwise, and then again along the fold to create a narrow, finished edge. The result is a robust, tidy finish that sits neatly on the outer surface of the fabric. Double-fold bias tape is a staple for necklines, armholes and hems on garments, and it behaves well on curves without bubbling or bunching.
Rolled-Edge Bias Tape (Bias Trim)
Rolled-edge bias tape is a specialty finish where the fabric’s edge is rolled into a narrow decorative edge. It’s often used on lightweight fabrics and adds a touch of detail to trims, aprons and heirloom pieces. This type requires careful sewing and sometimes a dedicated rolled-edge binder foot on the sewing machine.
Continuous Bias Tape vs Pre-Mfolded Bias Tape
Continuous bias tape is produced as a long length of bias cut fabric that you fold yourself according to the desired width. Pre-folded bias tape arrives already folded to a specific width, often with a crease line visible for easy stitching. For large projects or when you want consistent width, ready-made bias tape can be a real time-saver.
Width Matters: Common Bias Tape Widths
Bias tape is available in a range of widths. Common measurements include 12mm (½ inch), 18mm (⅔ inch), 25mm (1 inch) and wider varieties for heavy fabrics or decorative applications. When choosing a width, consider the weight of your fabric, how visible you want the finish to be, and how much you want the edge to blend into the design. For delicate blouses or baby garments, a narrower bias tape is often preferable, while coats or upholstery projects may benefit from a wider bias tape for a stronger finish.
Choosing Fabrics for Bias Tape
The choice of fabric to make bias tape from is important for both appearance and performance. Because bias tape cuts diagonally, it behaves differently from straight-grain fabric, and some fabrics drape more gracefully than others when cut on the bias.
Good Candidates for Bias Tape
- Light to medium-weight cottons, lawn, voile and cotton blends
- Silks and rayon blends for a softer, drapier finish
- Lightweight denim or chambray for casual garments
- Woven fabrics with a smooth hand and clear lines
Avoiding Difficulties
Steer clear of highly stretchy knits or fabrics with a heavy nap when starting with bias tape. Knits can move and stretch unpredictably on the bias, making it harder to achieve a neat finish unless you stabilise the edge. If you’re working with novelty prints or stripes, consider how the bias cut will affect pattern matching along the edge.
How to Make Bias Tape at Home
Creating bias tape at home gives you complete control over fabric choice, width and finish. The process is straightforward, though it benefits from careful measuring, precise cutting and thorough pressing. Here we cover both the traditional method and how to use handy tools such as bias tape makers to speed up production.
Traditional Method: Cutting on the Bias
- Choose your fabric and wash it to preshrink. Press flat and ensure it is completely dry before cutting.
- Determine the width you want for the finished bias tape. For a double-fold tape, you’ll typically cut a strip twice the desired finished width. For example, to end up with 18mm finished tape, cut a strip about 36mm wide.
- Position your ruler at a 45-degree angle to the fabric’s grain line. Using a rotary cutter or sharp scissors, cut long diagonal strips from corner to corner to create the bias strips.
- Repeat to obtain enough length for your project. Bias strips can be joined end-to-end with a diagonal seam (think of the seam forming a 45-degree angle) to create a continuous length.
Joining Ends to Form a Continuous Strip
To create long lengths of bias tape, join the ends with a diagonal seam. Align the strips at a right angle and stitch along the seam on a 45-degree angle. This continuous length reduces the number of joins along edges and creates a smooth finish around curves.
Preparing the Tape for Application
For double-fold bias tape, press the strip in half lengthwise with the wrong side facing inwards, then press each raw edge toward the centre crease. For single-fold bias tape, press the strip in half lengthwise and fold the raw edges inward toward the center crease if desired. A thorough pressing ensures a crisp crease that will stay defined during stitching.
Using a Bias Tape Maker: A Quick Method
A bias tape maker is a handy tool that helps shape bias strips into uniform tapes quickly. Thread the fabric through the maker, then fold and press as you guide the fabric through your iron. This method is particularly efficient for longer projects or when you need a consistent width across multiple strips.
How to Apply Bias Tape
Applying bias tape is where all the previous work pays off. The method you choose depends on the project and whether you’re aiming for a clean, visible finish or a discreet edge. Below are general steps for applying bias tape as bias binding to a garment edge, such as a neckline or armhole.
- Align the raw edge of the bias tape with the fabric edge you are finishing, right sides together. If you’re working with a narrow finish, you might place the tape slightly wider than the edge to allow for folding to the wrong side.
- Stitch close to the inner edge of the bias tape or along the fold line, depending on your preferred method. For a neat finish, stitching on the crease line or slightly inside the edge helps anchor the tape securely.
- Fold the bias tape to the inside of the garment and press carefully. If you’re using a double-fold tape, tuck the raw edges under the tape and press so you have a clean, finished edge visible on the outside.
- Topstitch along the outer edge to secure the bias tape in place. This can be done on both sides or just along the outer edge, depending on your design preference.
Tips for Curved Edges and Necklines
Bias tape shines on curves because of its stretch. When applying to necklines or armholes, ease the tape around gentle bends by repeatedly pressing and guiding the fabric with your fingers. For sharper curves, use shorter seams and clip the seam allowances at the inside of the curve to reduce bulk, then press again for a smooth finish.
Edge Finishes: Hems and Decorative Details
Bias tape isn’t limited to encasing raw edges. It can also be used decoratively to add a contrasting border, trim pockets, or highlight seams. For a decorative finish, consider contrasting bias tape or pairing a printed bias tape with a solid fabric to create a focal detail on your project.
Care, Maintenance and Troubleshooting
Bias tape finishes should be durable and maintainable. The following guidelines help you ensure longevity and a consistently neat appearance across washing cycles.
- Washing rhythm: Pre-washing fabrics before making bias tape helps prevent post-finish shrinkage that can pull at seams.
- Stability: Stabilise delicate fabrics with an interfacing or choose a bias tape that matches the fabric’s weight to avoid pulling or stretching.
- Ironing: Use a suitable heat setting for the fabric. A fabric press cloth can protect delicate tapes from scorching.
- Storage: Store bias tape in a dry, cool place away from direct sunlight to prevent fading and fabric distortion.
What is Bias Tape? Practical Projects and Applications
Across home, fashion and craft projects, bias tape can be the finishing touch that elevates the look. Here are a few ideas where bias tape or bias binding makes a visible difference.
- Bias-bound necklines on blouses and dresses for a clean, professional finish
- Armhole finishes that glide around the shoulder without pulling
- Decorative piping-like details on cushions and quilts
- Heirloom decline: bias tape used for dating and detailing on heirloom sewing pieces
- Children’s wear: soft, flexible bindings that are comfortable against delicate skin
Common Pitfalls and How to Avoid Them
Even experienced sewists can stumble with bias tape. Here are common issues and practical remedies.
- Puckering at edges: Ensure the fabric is properly pre-washed and that you’re using a stitch length appropriate for the fabric. A shorter stitch length can help minimize puckering on delicate fabrics.
- Bias tape stretching out of shape: Work with gently stretched strips, not taut ones. When applying, avoid pulling the tape as you stitch; allow the fabric to guide the edge.
- Visible misalignment at joins: Cut and join bias strips with precision, ensuring the diagonal seam is neat and lies flat. Finger-press joints before stitching to set the line.
Frequently Asked Questions about What is Bias Tape
Can bias tape be used on knits?
Yes, it can, but use a stabiliser and a stretch-friendly stitch such as a zigzag or a small length of a stretch stitch. Knit fabrics respond differently to bias cut finishes, so testing on a scrap before proceeding is wise.
Is bias tape the same as bias binding?
Not always. Bias tape is the material itself, which can be used to bind or finish edges. Bias binding is one common method of applying bias tape to edges to create a clean, enclosed finish.
How do I choose the right width for a bias tape?
Consider the garment’s weight, the edge being finished, and whether you want the finish to be bold or discreet. Lighter fabrics usually pair well with narrower bias tape (12–18mm). Heavier fabrics suit wider tapes (18–25mm or more).
What is the best way to finish a curved edge with bias tape?
Use a longer bias strip for smoother curves, clip the seam allowances at the inside of the curve, and take your time easing as you go. A shorter stitch length and careful pressing will help the tape stay aligned with the edge.
Conclusion: Embrace the Versatility of Bias Tape
What is bias tape, if not a small, adaptable tool that unlocks big possibilities in sewing? By understanding how to cut on the bias, choose the right width, and apply it with confidence, you can finish edges that look professional and feel comfortable. Bias tape is a classic technique that continues to be relevant—from delicate blouses to sturdy cushions and decorative trim. With a little practice, the art of bias binding becomes an enjoyable and rewarding part of your handmade wardrobe and home décor.
As you progress, you’ll discover that bias tape offers more than a practical solution. It provides a creative way to add colour, texture and structure to your projects. If you ever return to the question What is bias tape, you’ll find a technique that blends tradition with modern versatility, inviting you to experiment and refine your skills as you sew.