On both acoustic and electric fretted instruments, bone is the best sounding and most conductive material that can be used for the nut and/or saddle. It gives more presence and character to the sound. Plastics have a parametric or "black and white" tonal quality and bone has a "color" or full spectrum sound. The distinction is also akin to the difference between a solid wood instrument vs. plywood construction. In my estimation a bone upgrade improves the volume of an acoustic by 20ish%.

I carve them from a rectangular blank so that I can fine tune and customize an even string spacing across the neck, maintain optimal string contact, set the intonation perfectly, and set a comfortable custom string height. Nuts and saddles are a bottle neck for the path of the strings vibration, and contribute dramatically to the efficiency of the instruments that we ultimately enjoy hearing and playing.