Butternut lumber is cut from the butternut tree, Juglans cinerea, a member of the walnut family. Historically it was sometimes used as a substitute for its darker and tougher cousin, but this is less common today. Stocks of butternut in many areas are threatened by disease, making it scarce on the lumber market unless a mill has wood in reserve or works with reclaimed lumber. Woodworkers and other crafters concerned about sustainability may choose to avoid butternut lumber if they cannot find a recycled source because of concerns about the tree population.
A softwood, butternut lumber is easy to work, taking readily to hand and machine tools. It can be dyed, stained, and otherwise treated to change the color or bring out specific traits. Some butternut lumber has distinctive swirling patterns that may be brought out in milling for high-grade lumber intended for veneers and ornamental use. Overall, the wood tends to be lighter and softer than walnut, and is sometimes stained darker so it will more closely resemble walnut.
The coloration of butternut lumber can vary from a light tan to an almost cinnamon tone at the heartwood. Over time, it fades, especially if it is exposed to ultraviolet radiation. The rarity of this wood means it is a good choice for craft projects where it will be visible and is used for aesthetic reasons. It makes less suitable hidden structural material because of its softness and expense when compared to other woods.
Quality can vary depending on how the wood is processed and the condition of the original tree. It is advisable to check for knotting and splitting along each board before use to make sure it is appropriate for use, and to take note of any bowing or bending. Cured lumber should also be allowed to acclimate on site so it can adjust to any changes in temperature or humidity before it is used.
Outdoors, this wood can be subject to infestation with pests and mold because it lacks natural resistance. It is a good idea to treat butternut lumber that might be used outdoors, and to regularly re-treat these items to make sure they retain resistance to the elements. In especially harsh climates, it can be advisable to bring furniture and ornaments indoors for the winter to keep them in good condition. Limiting exposure to temperature extremes can also prevent bowing, peeling, and cracking that may damage finished pieces.