All that Glistens: A Century of Japanese Lacquer, on view in the North Building, features exquisite Japanese lacquers. The objects on view illustrate some of the specialized materials and techniques used in East Asian lacquer, the type historically made in China, Korea, and Japan.
East Asian lacquer has very particular conservation concerns due to the nature of its materials and construction. To care for it most effectively, it is important to understand how it is made and what factors contribute to its degradation over time.
Natural lacquer has been produced in East Asia since prehistoric times and was applied as a coating to protect and decorate a variety of objects such as household items, weapons, and musical instruments. The raw material, urushi in Japanese, is a milky sap collected from trees. The raw lacquer is collected, heated, filtered, and stored for use. The lacquer is applied in a very thin layer to a prepared substrate such as wood, metal, and leather and allowed to cure in a humid, dust-free cabinet for a day or longer. It is then polished and another layer is applied. An object may have only a few layers to more than a hundred.
The production of lacquered objects is a detailed and time-consuming process which involves many steps, specialized tools, and often a series of master craftsmen. The fabrication of the substrate to which the lacquer is applied may fall to one artisan, the preparation of the ground layers to another, and the final decoration to yet another. Lacquer may be used in its natural transparent state or colored with mineral or synthetic pigments. For instance, cinnabar and iron oxide are used to make red and black lacquers.
Lacquer can be decorated by embedding materials like metal, mother of pearl, and eggshell in the coating. Layers of lacquer are applied over these materials and then polished back down to reveal the decoration. The substrate itself can be molded or carved into intricate features and then lacquered to give a raised or embossed texture to the object. The Japanese invented stunning effects using metal powders known as makie. Select grades of powdered metals such as gold or silver are painstakingly positioned into the wet lacquer to create background effects or detailed compositions.
Although lacquer is a hard material once cured, it is very susceptible to various types of degradation and damage.
An environment with fluctuating temperature and relative humidity can lead to structural damage, such as cracks and loosening of joins in the substrate. Such changes in the substrate can in turn cause cracking and lifting of the lacquer coating. Thus, lacquer should not be displayed in spaces where temperature and humidity fluctuations occur, such as near heating and cooling vents, against outer walls, or in draughty areas such as doorways. Structural damage also can occur if the object is carelessly handled, dropped, or covered or filled with heavy items.
Surface damage can result from many factors. Excessive light accelerates lacquer degradation, causing it to lose its durability. Strong, direct light discolors the surface and dulls the lacquer’s sheen. To avoid light damage, lacquer should not be exposed to direct sunlight or high levels of intense artificial light. Closing curtains or applying ultraviolet filters to windows can help reduce damage.
Other surface damages include fingerprints, smudges and scratches. Cotton gloves should be worn when handling these objects, and they should be kept dust free, as dust is abrasive. To remove dust, use a soft brush such as a hake brush. It is safe to use a very slightly damp, soft cloth to further clean lacquer. Never immerse in water. Also, do not use commercial products such as Pledge or Endust, which may permanently ruin the lacquer finish. If lacquer objects require cleaning or repair beyond these basic steps, contact a conservator experienced with lacquer.
Finally, it is important to note that during the 18th century, many pieces of European furniture and decorative arts were japanned or “lacquered” using Western shellac to simulate East Asian lacquer. This technique of using various coatings and recipes in order to imitate Asian lacquer continues all over the world. It is important that owners of lacquer are aware that not all lacquers are natural East Asian lacquers.
Image credit: A person cuts a lacquer tree to collect the raw sap.