I found this wonderful tutorial and highly recommend you take a look at it. I am a long-arm quilter and I can't tell you how often I get wavy borders on a quilt top. I hate to put pleats in a customer's quilt but sometimes there is just too much fabric in the border to "quilt it out". If you follow this simple method, you will get beautiful, flat borders and I can't tell you how much your quilter will appreciate it. Please take a look and make your next quilt perfect.