It would be interesting if Wrench had something else to add.
Dermot

Gee thanks WrenchSorry it took me so long to get back here. I have very little spare time these days. Here are the photos I promised demonstrating the clearance I put on the back side of saddles.
EDIT: Crap! how do attach photos?
Michele, you are a courageous and skillful lady to experiment with these saddles. I think you need to look for no one more professional than yourself and perhaps a couple of improved tools to make an improved saddle. It sounds like you had some success experimenting, and I am very impressed with your efforts.
If you think you have an edge sharp enough to damage a string, you need only to break that edge with a very small file or my personal favorite saddle tool, the radiused notch in a utility knife blade.
Your observation of bone are pretty spot on, too. I find bone to offer the loudest and most fundamental response of the nut and saddle materials. TUSQ is equally dense and loud, but it passes some much higher frequencies than bone.
Guitar compensation and intonation is the most elusive science I know of. As far as I know, the only two people to achieve concrete science on the subject are Greg Byers (nylon string only) and Trevor Gore, who extended Byers' work to steel strings, and uses that information in his products. Incidentally, Gore is an Aussie. Many others have written papers on intonation, but they always contain the words approximation, estimated, and trial-and-error. And you took it on. Be proud.
:laugh: :laugh:Dermot - Thanks. You've just got to jump sometimes and hope you learn to fly before you hit the ground. Right?