I just finished cutting a scroll sawed picture in a piece of black walnut. I normally apply 50/50 MS and BLO as a finish to my pictures, but I do not want to have the wood darken because of the finish. Anything I have ever used on black walnut makes it much darker than is natural. It there some finish that will not darken it much? I know anything will darken it a little. Or is it best to leave it without a finish?