Homespun is one of those fabrics that is made with the thread already dyed when it is woven ;think of a rug on a loom, versus using a gris (base fabric) which is then dyed. That is why the thread 'is the grain'. When I worked at a fabric store, we chose a thread and cut following that thread. Sounds like your pieces were not cuy that way so if it is important to keep the pattern straight, yes, you will have to trim. I hope I helped explained.