A woven fabric is created when threads are linked under and over each other. The threads that run lengthwise (up and down parallel to the selvedge) are called WARP threads. The threads that run across the fabric (from side to side and selvedge to selvedge) are called the WEFT threads.
If the fabric is placed on the diagonal, then it is on the "bias". The warp and weft threads run at 45% and the fabric "moves" more fluidly than if they run up/down and across.
A garment that is constructed with fabric that is cut on the bias (like the Bias Cami), moves with the body and is very comfortable to wear.
BIAS TAPE (or bias binding) is a long thin strip of fabric that is cut on the bias. Because it moves fluidly, it is often used to finish a curved edge in garment construction because it bends around the curve without puckering or folding.
ATTACHING BIAS TAPE: Learn how to attach bias tape to a neckline here. The same principles apply to attach the bias tape to any curve.
HOW TO MAKE YOUR OWN BIAS TAPE:
In this image the fabric was not a square - I used the scraps left over from the garment.
- Fold your fabric so that the fold line is at 45 degrees across the warp and weft threads. For example, if your fabric is cut in a square, put your finger on the bottom left hand corner and using your right hand, bring the RHS bottom corner up to meet the top LHS corner so, what was the bottom edge is now aligned with the left hand edge.
- Press the folded edge
- Mark a line that is twice the finished width you desire plus a small seam allowance. If you want your finished bias edge to be 1cm, you will need to cut a strip that is 3cm wide (on the fold). If you are comfortable sewing a 0.5cm seam then cut your fabric at 2.5cm wide (on the fold).