A dull needle is not good change often. Bearding can occur for one. It is when there are white dots appearing on the fabric caused by the batting coming thru from a dull needle. Someone mentioned popping noises from punching thru material breaking the threads from a dull needle. also skipped stitches come from a dull or bad needle due to the scarf on the back side out of shape so as not to pick up the thread from the hook properly. A new sharp needle is a small thing but very important. I have only been quilting for a short time. My mother was a seemstress for years and her advise to me "change your needle often" :)