Introduction
Bias cutting is a special technological area where the properties of the
fabric become more pronounced than when the fabric is cut along the
grain.
The bias gives garments softness, natural movement, and beautiful
draping, but at the same time it makes the material vulnerable to
stretching, distortion, and loss of balance.
Therefore, in this case, the patternmaker’s work begins long before
drafting the pattern — with a careful study of the fabric.
This seminar is intended for beginner patternmakers. It explains the
specific features of working with garments cut on the bias:
- fabric testing,
- pattern adjustments,
- choice of construction ,
- methods of edge finishing,
- causes of defects.
Fabric Testing Before Pattern Construction
Before starting the pattern construction, it is important to determine how suitable the fabric is for a garment cut on the bias. The bias greatly intensifies every property of the material, so preliminary analysis is the basis for the future accuracy of the patterns.
Determining the warp and weft: To reliably determine the direction of the threads, make a small cut along the selvedge and tear the fabric across its width. The tear always follows the weft. The torn edge is then placed against the right angle of a table or ruler.
Signs of good-quality fabric:
- the threads intersect at a right angle;
- the tear runs evenly;
- there is no diagonal displacement.
If the angle is distorted, the fabric will behave unpredictably, and the
distortion will increase when the garment is cut on the bias.
Conclusion
This material is a brief introduction to the principles of 45° bias-cut garment construction.
For a complete study of the subject, including pattern development, fabric preparation, pattern adjustments, and defect prevention techniques, we recommend exploring the full course:
“Bias Cut Garment Construction: 45° Bias Techniques for Fashion Designers”