I get a lot of requests for light, medium, or dark figured spacers. The three spacers above show this variability even after being stabilized. All three of these spacers came from the same piece of lumber that I brought back from Hawaii three years ago while visiting my family. By cutting the wood while paying attention to the cross-grain you can get this variability from a single piece of Koa especially if it is slightly spalted. Figuring refers to the appearance of wood, as seen on a longitudinal surfaces. The side-grain of "figured wood" is not plain but has a curly sheen.
The figuring on a particular piece of wood may be due to the cut, or to innate properties of the wood. Some tropical hardwoods, like Rosewood, maple, and Koa can have quite spectacular figuring. Colloquially speaking "figure" is often referred to as "grain."
Nomenclature describing figuring include bear scratches, bird's eye, blister, burl, curl, dimple, fiddleback, flame, ghosting, quilted, and spalting. Many people from different regions around the world describe it differently. Curly wood is believed to be caused by wind swept conditions in its given area. The striking wave-like patterns are highly sought after by woodworkers. Curl is also commonly referred to as fiddleback for its traditional use in making musical instruments especially stringed instruments.