don't really know what you are asking. If you have been reading how to find the straight of grain in fabric, you know to pull a thread across the WOF. and you probably also read that not all plaids follow the straight of grain, especially if the fabric was printed off grain during the manufacturing process. Homespuns are usually "woven" on grain so the plaid will match the grain. Again, you can confirm this with a simple thread-pull test. As I pull the thread, I usually trim the fabric along the pull line so my fabric finishes to be cut on the grain line. If this line is not 90 degrees off the selvage, I then pull the fabric from corner to corner to straighten the fabric. This is essential when making draperies and well draping garments, not sure it is necessary in quilting.