I cut the corners. Then I can use the corners to test for colorfastness. I also save the threads that do come off. I trim them after the wash and before the dryer. I set my pile of strings on the dryer and when it is dry, I put it in the bag with the rest of my collection! Someday they will be sandwiched between two layers of batiste or organza to make my own desingner fabric for art quilts. Just haven't gotten there yet!