Just a collection of wood types I've narrowed my use to. When I started I bought almost every wood type I could get my hands on and over time, have learned that some of the most beautiful do not keep their luster unless you keep it in a dark, air-tight box buried somewhere. Purples turn to brown. Yellows turn to brown. Even Brown turns to brown. So the wood types I've chosen may discolor over a long period of time, (Wood Database} at least mine will be far longer than most.