Martin guitars used to use micarta for nuts. Not sure about saddles. When my supply business was more active I bought black and white micarta in 3/8" x 24" x 48" sheets. There are several kinds of micarta. What I use is the one called Paper. It does not show any grain and polishes like glass. Some of the other types like burlap or linen will show grain patterns and that does not work well for nuts and saddles. I've been using it for almost 40 years. Black micarta is generally cheaper than white micarta because they don't need to care about imperfections in the color. White micarta is more tricky. Any weird foreign stuff in the epoxy mix often shows up as a solid strata line and often can't be used. Seems the quality of white was better years ago. The white would develop a nice yellow bone like patina, which might be why Martin used it. It works much like bone, maybe a bit softer. I like using it.
