Wenge: Black Lines on Coffee Brown

Wenge (Millettia laurentii) is a tree that grows in Central Africa, including the Congo. Its heartwood is a deep coffee brown, closely overlaid with black lines. Heavy and hard, it is used for furniture, flooring, handles, and musical-instrument components. Seen from a distance, it looks almost black, but up close, the distinct lines of brown and black running alternately across the surface become clear.

Wenge board (No. 1966). Deep lines run across the full 732 mm length.

When the Lines Become Waves

Wenge’s lines are basically straight. But when the board is cut at an angle, the same lines appear to overlap like waves. The pattern is often called tiger striping. Around knots, the lines curve widely and wind outward, becoming noticeably thicker around them. In square boards that have been neatly finished, short lines connect in zigzags, and the pattern appears to change depending on the direction of the light.

Wave patterns curving around a knot (No. 1966) and lines connected in zigzags (No. 4911).

A Dark Interior, a Bright Edge

Wenge also has a strong color difference between its heartwood and sapwood. The sapwood near the bark is a pale grayish brown, so boards retaining sapwood along the edges naturally develop a bright border around the dark heartwood. Some 45 mm-thick boards have a large void through the middle. These are traces left where rotten or split sections have fallen away; such areas are sometimes filled with resin and given new life as tables or objects.

A board retaining bright sapwood on both sides (No. 3602) and a board with a large void through the middle (No. 2816).

Blocks, Slices, and Log Sections

There is more than just board stock. A long block measuring 1,645 mm in length and 94 mm in thickness looks like a pillar when stood upright. A large 590 × 725 mm round slice has closely spaced growth rings running from the center to the outer edge, with the bark-side form preserved around its perimeter. A short log section displays distinct stripes crossing its round face.

A 1,645 mm-long block (No. 5910), a large round slice (No. 1600), and a log section (No. 4614).

What to Know When Handling It

Wenge has a coarse grain. Splinters rise easily when it is planed or sanded, so it is best to wear gloves when working with it. Once finished, however, its deep color and striping give even small pieces a strong presence. A partially worked piece cut into a butterfly shape can be finished as a butterfly key for furniture joinery or as a pendant.

A partially worked piece of wenge cut into a butterfly shape (No. 3752).

Even with the same wenge, straight or wavy lines can appear depending on the direction in which it was cut. Every piece of solid wood is unique, so the same pattern will never appear again.