I don't, I cut my borders the length of the fabric at the very first, and yes I do sometimes have to seam them, but I do this because it will never stretch, where WOF will. I cut a generous length to make sure I have enough, then when the time comes to put them on, I measure thru the center of the quilt, to give me the measurement, then cut both pieces that exact length, and ease in the sides to fit the border length. Then repeat this for the other sides. Sometimes I miter and sometimes not. Jan