Bias is a term used to describe a fabric or garment that has been cut diagonally across the grain rather than parallel to the weave. This results in a material that has more stretch and drape than one cut on the straight grain, making it particularly useful for creating garments with a close fit or fluid drape.
When fabric is woven, the warp and weft threads are interlaced at a right angle, creating a grid-like pattern. The bias of the fabric is a 45-degree angle relative to the warp and weft threads. Cutting along this angle means that the fabric's threads are no longer straight, resulting in a unique and stretchy material that can be used for a variety of applications.
Bias-cut fabric can be used to create a range of garments, from fluid dresses and skirts to fitted bodices and lingerie. The stretch in the material allows for a closer fit to the body, while the drape creates a flattering silhouette. Bias-cut garments are often associated with the glamour of the 1930s and 1940s, but they continue to be a popular choice for designers and home sewers alike.
One of the challenges of working with bias-cut fabric is that it can be prone to stretching and warping during the cutting and sewing process. To avoid this, it is important to handle the fabric carefully and to use techniques such as stay-stitching to stabilize the edges before sewing.
Some fabrics are more suitable for bias cutting than others. Lightweight and drapey fabrics such as silk, rayon, and chiffon are ideal for creating fluid bias-cut garments, while heavier materials such as denim and wool can be used for more structured designs. The diagonal cut of the fabric also means that patterns and prints will appear different on bias-cut garments than they would on straight-grain pieces, adding another dimension to the design.
Bias-cut fabric can also be used for a variety of other applications in addition to garments. Quilters often use bias binding to finish the edges of quilts, and bias tape can be used to create neat and professional-looking finishes on a range of projects.
Some of the top manufacturers of bias-cut fabric include Liberty Fabrics, Tencel, and Mood Fabrics. Liberty Fabrics, based in the UK, is known for its high-quality and vibrant prints, while Tencel, a sustainable fiber company, produces a range of soft and drapey materials suitable for bias cutting. Mood Fabrics, based in New York City, is a popular destination for home sewers and designers alike, offering a wide range of fabrics suitable for bias cutting and other applications.
In summary, bias refers to a fabric or garment that has been cut diagonally across the grain, resulting in a material with more stretch and drape. This type of fabric is ideal for creating garments with a close fit or fluid silhouette, and can be used for a range of other applications such as quilt binding and finishing. Bias-cut fabric requires careful handling and can be prone to stretching and warping, but the unique properties of the material make it a popular choice for designers and home sewers alike.
The bias direction of a piece of woven fabric, usually referred to simply as "the bias", is at 45 degrees to its warp and weft threads. Every piece of woven fabric has two biases, perpendicular to each other.
Cut diagonally across the grain of a fabric. Used to create garments that follow the body curves closely. A bias cut is any direction in the fabric which does not exactly flow in the direction of the weft yarn (vertical yarns) or warp yarns (horizontal yarns) of a fabric. A true bias makes an angle of 45 degrees across the length and width of a fabric. Fabric cut on a bias has maximum stretch.