What is lacquer?
Lacquer or urushi, in Japanese, is the sap of the tree rhus verniciflua which is related to the sumac. Through out the spring and summer the bark of the tree is slashed to collect the sap which is then processed to produce raw urushi.Raw urushi is used for lacquer ware base preparation. Refined urushi is used for final coating and decoration. The amount of sap collected from each tree is only 250 milliliters per year making urushi a very precious commodity.
Urushi drys by polymerization in moist air not by the evaporation of a solvent as with most paints. The urushi molecules join together forming a hard, lustrous and durable coating. Beauty combined with durability is one reason that the art of lacquer ware has been practiced for thousand of years. Many examples of lacquer ware objects which are over two thousand years old exist in Museums around the world.
Care of lacquer ware
Lacquer is used on many items which receive heavy wear such as furniture and kitchenware. Despite the fact that new lacquer is one of the most durable coatings around it does require care to retain its beauty for many centuries. Lacquer is easily damaged by light, especially ultraviolet light. The surface of the lacquer ware will fade and become dull as light breaks down the urushi molecules. Light damage is permanent just like the fading of a textile. Under magnification, one can see that the dull appearance is actually a network of very fine cracks that have formed on the surface of the lacquer ware.
Once light damage has occurred, other deterioration can happen as well. Surfaces that were once durable enough to be used for hot soup now become soluble in water. This means if you put a wet drinking glass on an light damaged urushi surface it will leave a mark that cannot be removed. Fingerprints that are not wiped off immediately will also become permanent.
Lacquer ware is also susceptible to damage from very dry conditions or fluctuating humidity. When homes are heated in the winter the humidity level often drops very low. This can cause the wood core to shrink and cracks will form in the lacquer. Once the cracks have formed further damage can occur more rapidly. If lacquer is exposed to cycles of low and high humidity the lacquer will eventually start to flake off its wooden core. It is important not to let the humidity drop too low or fluctuate wildly if you want to keep lacquer ware in prime condition. In museums, a constant humidity of 50 to 60 per cent is usually recommended.
Conclusion
To preserve the beauty of your lacquer ware you should never leave it in direct sunlight or displayed under fluorescent lamps. In Japan the most valuable pieces of lacquer ware are stored in silk bags or wooden boxes and brought out for special occasions. With these few precautions you should be able to enjoy the beauty of your lacquer ware for many years.
Material provided by Ms. MARIANNE WEBB,
Decorative Arts Conservator at
ROYAL ONTARIO MUSEUM.
