I am always trying to come up with a way to do a spiral inlay. Here is as close as I have come thus far. Walnut inlay on curley maple. It spirals nicely the length of the pen. Picture could be better.
I turned the blank round first. Drilled holes halfway into the blank on the drill press then glued walnut dowels in the holes. I drilled it after rounding so the inlay would not distort. Then I drilled the blank and proceeded as usual. The trickey part is figuring out the spiral ratio so it spirals correctly when open as well as closed. Thanks for the nice comments.