Never Fear Bias Strips Again!
So to cut a bias strip, since this is a short strip I don't need a lot of fabric, I'm going to line up my ruler which has a 45 degree line on it and line up that 45 degree line with the bottom edge of my fabric strip, then I'm going to cut along the edge of the ruler and that's going to give me a 45 degree angle or a bias angle. The reason I want a bias angle is because the bias of a fabric stretches a little more than the straighter grain does and that will allow that little loop on the bag to actually give a little bit as it wraps around the button. Now that I've got the 45 degree angle, I'll line up the 1 1/8th mark on my ruler and I'll cut my strip. At that point you can straighten up those ends and see how long of a strip you need to wrap around your button.