What is a bias cut fabric used to finish garment edges?

Looking closely at a square of fabric, you will see a thread that runs vertically and a thread that runs horizontally, this is galled the grain of the fabric.

Bias cut fabric is fabric that is cut diagonally to the grain. In other words, if you cut off a corner and then cut another strip at the same diagonal, say 2 1/2 inches wide, you will have a bias cut fabric. this strip of fabric can then be folded taking both outer edges toward the center and then folded again in half. It can be used to finish anything from blankets, quilts garments etc. as it is very bendable and pliable because it stretches as a result of being cut on the bias.