Originally Posted by
bjchad
Your fabric is what my mother used to call "swivven". Gently tug diagonally opposite corners until it straightens up.
My mom used a different term, but to the same effect. For garment construction, the fabric grain is much more important than in quilting. We would cut one edge on grain (WOF), often pulling a single thread to determine the grain. Then pull opposite corners. We weren't gentle! Keep checking by folding the fabric with selvedges together until it hangs correctly. For quilting, it's not as important because you aren't looking for the fabric to drape. Unless you want to use the fabric exactly on weave for design purposes, just starch it and pick one for the straight.