Finding your grain can often be the most difficult part of beginning a project. However, if you clip into the selvage just a bit and pull on a loose thread, you can easily find the grain. The loose thread will tug on the fabric and you can pull it out gently. This line that is left is your cross-grain and the cross-grain runs perpendicular to the grain line. Once you fold the fabric in half, your lines should match on both sides. Source and more info: colettehq