You asked for it, you got it. Here's an instructional video from Heirloom Creations that describes how to use three different Bernina Bias Binders, including how to attach, by machine, a binding to a mitered (square, not rounded) corner. The Bernina Bias Binders used are the #85 Simple Bias Binder, and #87 and #88 Binder Attachments.