I was gifted with Creative Grids 20 1/2" square at our guild meeting as a thank you for teaching a workshop on paper piecing. They were mostly beginners at paper piecing & some were beginners at quilting. I decided that they should learn with the Mariner's Compass - no challenge there! All of these wonderful ladies finished setting their compass in the setting square! They had a great time and loads of fun. I have used this ruler so much lately, it may just be my new fav!