i reread your original and you ask about joining not cutting on the bias. Joining on the straight causes the eye to stop at that point. Joining on a 45 degree cut looks better as the eye moves along the border. If it is a gtrue 45 degree there should be any waving or wobbling. And even if you didn't have enough fabric to cut on a tru 45 degree, any degree will do as long as it is true. I have joined at 60 degrees and other in order to keep the eye flowing along the border.