The Quilty™ Scope by Riley Blake Designs helps you see what fabrics blend or contrast too much in your projects before getting started. It keeps you from overpowering your project with one color. It's excellent for batiks or any printed fabric. Here is a link to a video tutorial https://youtu.be/ssJFEeYrTCE?si=FlKayzd7dfZ9sWC8. It's also included on the package.