Yes needles do get dull. You can damage your fabric when you try to sew with a dull needle. Ball points are for knits. Get some universal needles they work really well for cottons. The needle should be changed every 6-8 hours of sewing or even sooner if your thread is shredding or breaking then you really need a new needle. If you are using decorative thread then you should use a large eye needle for ex: 14/90