I purchased a square ruler with X lines on it several years ago at the Quilt Festival in Houston that had "Sharon's" on it. I did not purchase the book, only the square, and thought I can remember how to do this from watching a demo. But....there was so much info there that it was overwhelming, and I didn't remember how to use it. So, which came first? I think it was "Sharon's" ruler. I googled and never did find info. on it.