Sliver-thin, delicately cut, and masterfully assembled into breathtaking images and patterns; one does not need to know much about marquetry to understand the skill it requires. A process dating back thousands of years, marquetry is the beautiful result of years of training, perfection, and artisanship.
Marquetry, Inlay, or Boulle?
The end results might look very similar, but there are some distinct differences between these three techniques. The description ‘“inlay” may come to mind when you see the intricately pieced elements of marquetry, but inlay has a distinctly specific characteristic: inlay involves carving a recess into a surface and placing a second material into the recess. Marquetry involves carving multiple pieces to fit together perfectly, like a puzzle, and the substrate to which the pieces are glued is not a part of the image.
Boulle is a specific style of marquetry, named for its creator and perfecter, André-Charles Boulle (1642 – 1732) who used brass and tortoise shell to create more luminous designs than could be done with wood veneers. Today, Boulle is still considered to be the master of this technique. Boulle was employed at Versailles after being granted a gallery at the Louvre Palace by French monarch Henri IV - a privilege only bestowed to artists favored by the king.
The Challenges of Conserving Boulle
As a every conservator knows, as the number of mediums in an artwork in increase, the corresponding conservation treatment grows exponentially more complex. Temperature, humidity and the passage of time each have different effects on the brass, tortoiseshell, wood substrate, and glue used to create a piece of Boulle furniture. The result is loss of pieces, pieces that no longer fit together the way they are meant to, and discoloration and tarnishing of the surface.
As a result, there are a number of relatively unique difficulties that Boulle marquetry presents to conservators. Senior Furniture Conservators Stephen Ryan and Michael Young have had the privilege to conserve some exceptional marquetry items, and have seen many different challenges. Traditional marquetry uses wood veneers on a wood substrate, and the materials react to atmospheric changes similarly. In sharp contrast, Boulle is made from brass and tortoise shell, neither of which will expand or contract nearly as much (if at all) as the wood substrate to which they are attached. As Stephen and Michael note, the differences of the materials “create significant stress between the substrate and the marquetry, which inevitably causes the glue holding the Boulle-work in place to fail.”
Once the glue fails, it is likely that pieces of the marquetry will be lost, making it the conservator's task to create appropriate replacements - which presents another set of challenges. Some restorers may attempt to fill brass losses with non-metal fillers, but as Michael notes, “the color and the luster of such fills never adequately match the original brass.” Tortoise shell presents another hurdle; like ivory, tortoise shell comes from a protected species and is no longer legally obtainable. Fortunately, there are synthetic tortoise shell materials available which are a reasonable approximation of the original. Stephan and Michael have found that for the best visual repair, the damaged and lost marquetry should be replaced using brass and quality synthetic tortoise shell. “These repairs take longer, but are much more effective in the long run.”
On most furniture, an age-related patina is considered desirable and attractive, enhancing the look of the antique. Boulle furniture is an exception to this general rule. Traditionally, Boulle furniture was finished with a high polish, so the brass in the marquetry was made to look golden to match the gilt bronze ormolu ornamentation. However, brass is prone to oxidation causing it to develop a greenish-brown patination over time that inevitably leaves the brass looking discordant. A freshly polished exterior enhances the quality of the materials and provides an appropriately attractive surface to any Boulle item.
“Boulle, André-Charles, the elder” https://www.getty.edu/
The American Marquetry Society http://www.americanmarquetrysociety.com/