Sewing & Pattern making Terms


In sewing and pattern making, “bias” refers to a diagonal direction across the grain of the fabric. The bias is a 45-degree angle in relation to the straight lengthwise grain (parallel to the selvage) and crosswise grain (perpendicular to the selvage) of the fabric.

The bias of the fabric has unique characteristics and properties that make it useful in various sewing techniques and garment construction.

Here are some key points about the bias:

  1. Stretch and drape: The bias has inherent stretch and fluidity, making it ideal for creating garments that require ease of movement and a draped, flowing appearance. When fabric is cut on the bias, it can mold and contour to the body more gracefully than when cut along the straight grain.
  2. Bias binding: Bias binding is a technique where strips of fabric cut on the bias are used to encase raw edges, finish hems, or create decorative trims. Because the bias has a natural stretch, bias binding can easily curve around curves and edges, providing a clean and flexible finish.
  3. Seam finishes: Bias strips can also be used as a seam finish or to join fabric pieces together. The bias tape is sewn along the seam line, encasing the raw edges and providing a neat and durable finish.
  4. Pattern making: Pattern makers often utilize the bias to create specific design details or to accommodate curves and contours in the body. They may incorporate bias panels or bias inserts to add visual interest or enhance the fit of a garment.

When working with the bias, it’s important to handle the fabric carefully, as it is more prone to stretching and distortion compared to the straight grain. Take care when cutting and sewing on the bias to maintain the desired shape and fit of the garment.

Understanding the bias and its properties allows seamstresses and pattern makers to utilize this diagonal direction creatively, resulting in garments with beautiful drape, flexibility, and visual interest.

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Melissa Villegas
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