The French have a term for marquetry. They call it “painting in wood”, and to a degree that is exactly what it is. Different woods are chosen according to their color and figure depending on the needs of the image. The problem with this description, however, is that the color palette offered by nature is constrained. Predominately brown, woods range in hue from oranges to yellows. Greens are quite limited. Occasionally, exotic species provide materials outside of this range, reds and purple, for example, but I know of no blues. Faced with this situation, the marqueter must decide whether to adhere to these limitations, or try a different route.
One answer has been to dye veneer to the shades needed. Wood, usually light colored, is cut, or sliced into thin sheets which are immersed in vats containing the appropriate dye liquid. This offers great flexibility as, conceivably, any color veneer should be possible. According to Arlen Heginbotham, Associate Conservator in the Decorative Arts and Sculpture Conservation Department at the J. Paul Getty Museum, this was Oeben’s solution (pun intended). Though this appears obvious in hindsight, it was not always the case. One of the difficulties in assessing old marquetry is that the dyes are unstable. So, the colors of the woods deteriorate with time, making it difficult to conclusively identify species. During my initial studies of the marquetry top, I consulted three sources for wood identification. Each of them differed significantly! Wood that one source claimed was ebony, was actually holly whose green dye had morphed into black with age!
Thankfully, modern dyes are more colorfast. However, they are not without their issues. For starters, it can sometimes be difficult to obtain the appropriate veneer. Holly and boxwood, for instance, are currently vexing. Having different densities, and properties, each species behaves uniquely. Just because two woods are “white” doesn’t mean they’ll result in the same color when dyed. The next challenge comes in determining the proper color “recipe”. Experimenting with differing concentrations on samples is the only certain method of which I’m aware to address this. As you can imagine, it’s a slow, resource intensive process, which isn’t perfect. The goal is to get uniform color throughout the thickness of the veneer. That way the color doesn’t disappear when the completed surface is worked. Owning to the nature of wood, I have a harder time making this happen with light versus dark colors. Orange on sycamore, for example, still hasn’t completely permeated after more then 16 hours of boiling (with two plus weeks of sitting in a cold bath!) while dark green took about eight.
And so it goes, cooking small five inch squares in test batches until the “proper” color is achieved. Waiting a day or two for the wet sample to dry. The true color doesn’t show until the excess moisture has been removed. Then it’s on to production. At this point, I have a green I’m pleased with, and an orange that I think will work. That leaves a blue, light purple, and two more shades of orange. Looks like I’ll be cooking wood for a few more weeks…