I guess I never thought about the selvedge edge being missing from precuts, because I remembered from a junior high school 'Home Economics' class that you could find the straight of grain in small pieces of fabric, if you remember that woven fabric has some 'give' across the grain but almost none on the straight of grain. I just do this automatically when I have an piece that is no longer yardage, before I cut. Doing this will also make it easier to piece because all of the stretchiness will be one direction on any quilt made with right angles, so I get more accuracy. My corners are not always perfect, but at least I know I have done all I can to get it that way. Lol!