Cutting fabric on the bias is easy, and very effective! All it means is that, rather than cutting your pattern in the usual vertical / horizontal format you would normally use, you cut at 45 degrees to the weave of the fabric. Have a look at the diagram and see that the long straight line on the pattern, rather than running along the edge of the fabric, is running at 45 degrees.
This does only work on woven fabrics – if you are using a felted or other non-woven then it doesn’t really have any effect. But on a woven fabric, this diagonal cutting has an amazing result. It makes use of the natural stretch that even a non-stretch fabric has.
When cutting fabric on the bias it is useful to remember that every piece of woven fabric has two biases, at 90 degrees to each other. They both work pretty much the same.
The “bias-cut” is a technique used by designers to accentuate body lines and curves and drape softly. For example, a full-skirt cut on the bias will hang more gracefully and a narrow garment, such as this beautiful 1930s dress, will cling to the figure. Many of the elegant designs from the 30s and 40s use the bias cut technique.