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.
Walnut works easily with hand and machine tools, and nails, screws and glues well. It holds paint and stain very well for an exceptional finish and is readily polished. It dries slowly, and care is needed to avoid kiln degrade. Walnut has good dimensional stability.