I learned about this in a class. I love mine, and I have the add an 1/8 too for small pieces. I have both 6 and 12. inch, and now I want the 18 inch. My PP is far better now that I'm using it. Suggest you look for the YouTube video to learn how to use it properly. Also, i read on a blog (American Quilter?) recently how to use it for cutting with templates. A useful tool. Love it.