I recieved a set of Pirastro Obligato's in the mail today and can't wait to try them out. I'm going to take my bass to the luthier and have him make some other adjustments/repairs to the bass, and install the strings. How wide do the nut slots need to be made so that the strings will not break at the nut? I will also have him use plenty of graphite on both the nut and the bridge, as suggested. Is there anything else I should tell him?