A small addendum to Sean's comment on round grooves. A hobby shop or a hardware store should have sets of the small "Swedish pattern" files. One of those is a tapered round (or rat tail), and the end of that is quite small and good for rounding grooves. You don't need an expensive set as the nut isn't that hard, many sets of three (triangle, round and flat) cost only about five bucks US. But be careful if you do it, you don't want to go too far. Work a bit, try the string, then work a bit more. You don't have to unstring, just slacken the one you are working on and move it over it's neighbor on the nut and retighten - that way you can maintain the tension so the string doesn't relax.
Best, Jon > > Just before you try everything at once :^) I prefer beeswax to graphite > since it doesn't leave black marks on your nut. But definitely make > sure your grooves are round (and a slightly greater radius than the > string) first. > > Sean Smith To get on or off this list see list information at http://www.cs.dartmouth.edu/~wbc/lute-admin/index.html