The sapwood of walnut is creamy white, while the heartwood is light brown to dark chocolate brown, occasionally with a purplish cast and darker streaks. The wood develops a rich patina that grows more lustrous with age. Walnut is usually supplied steamed, to darken sapwood. The wood is generally straight-grained, but sometimes with wavy or curly grain that produces an attractive and decorative figure. This species produces a greater variety of figure types than any other.