Lacquer-ware

Lacquer or shellac was sometimes layered to produce a material that could be carved or molded. Popular examples of this process are the red Asian cinnabar ware and union cases used for early photographs. Most cinnabar-ware actually contains no cinnabar, although this toxic sulfide of mercury was originally used as a coloring agent. Some of this lacquer-ware is composed entirely of many layers of lacquer, but most has a base of wood or metal. 

The lacquer used in traditional Chinese or Japanese carred lacquer ware is derived from the resin of the tree Rhus verrac eroy which grows wild throu out China, especially on high plateaux. 

The sap of a shrubby tree growing over large areas of Asia has been used to produce a highly durable protective and decorative coating for a wide variety of objects. The finished material, called lacquer, is known to have been used for over 3700 years. It is seen on utilitarian everyday objects such as boxes, trays, and cups, and further serves as a protective and decorative coating on furniture, armor, masks, and sculpture. Furthermore, lacquer ware continues to be used and remains highly prized even today. 

The methods of collecting and refining the raw materials and the production of objects are very labor intensive. Even before the final decoration is applied, the manufacture of high-quality lacquer ware involves up to 30 difierent processes. These include steps in preparation and stabilization of the inner core, application of an undercoating to reinforce the core, and application of the intermediate lacquer layers, each polished and prepared for final decoration. These last decorative procedures may require a great number of multiple layers incorporating a variety of materials. 

The unique qualities of lacquer ware fully justify this effort. Once hardened, the lacquer surface protects from dampness and mold is relatively scratchproof and remains unaffected by alcohol, hot water, salt, and alkali solutions. Even with everyday use (employing proper care), lacquered objects can survive in an excellent state for a very long time. 

Lacquer differs entirely from varnish and lac, although the terms may be mistakenly interchanged in the literature. Varnish is a natural resin dissolved in a solvent. After the solution has been applied, the solvent volatilizes, leaving a shiny glaze. Lac is the deposit of the Coccus lacca insect, which is collected from certain trees in East India. This deposit is refined and dissolved in a solvent. Both varnish and lac coatings are much less stable than the coating found on oriental lacquer ware. 

When properly produced, a lacquer film is extremely durable. It is unaffected by most acids, bases, alcohol and water at room temperatures. One common usage of lacquer ware is for food storage. Lacquer films are, however, sensitive to UV radiation and extremes of heat both may cause irreversible discoloration. 

Early discussions on lacquer ware in occidental publications are rare. An article by Father dlncarville in 1760 (9) appears to be one of the first containing information on lacquer composition and uses. This is followed in the late 19th century by reports by Wagener (JO), Maeda (JJ), Rein... 

Over the past hundred years numerous experimental methods have been used for the study of urushi and the finished lacquer ware. The first recorded reports on chemical experiments are those of Ishimatsu (14), Yoshida (13) and Korschelt and Yoshida (15). Miyama gave the name urushiol to urushic acid (16), and he and Majima and coworkers (17-26) further explored the composition of urushi. Work by Sunthanker, Dawson, and Symmes (27,28) helped to determine that it contained three substituted catechol derivatives containing various diflFerent side chains. The previously mentioned reports by Kumanotani and coworkers (1-7) have allowed us to understand more of the details of the raw urushi, the complex mechanism of film hardening, and some properties of the hardened layers. 

The final example of new instruments for lacquer analysis uses IR spectrophotometry. Kenjo has pointed out how useful IR spectra can be when used for provenance studies (39,40). M. J. D. Low, of New York University, has recently developed an IR instrument that is nondestructive no sample taking or preparation is required (58,59). Use of this instrument will prove to be extremely important because of the value of some lacquer ware and the justifiable reluctance of curators to allow samples to be taken. We are currently evaluating this new instrument s performance with lacquer. 

Coating operations organic solvents lacquered ware... 

Despite historically long human experience of the use of the lacquer wares, there was no scientific data evidencing the excelling durability of Japanese lacquer when we began the study of Japanese lacquer in our laboratory. 

High durability of the lacquer films has been recognized through long human experience and use of lacquer wares. 

Today most lacquers are made with cellulosic, alkyd, acrylic, and vinyl resins. (2) Finish on Chinese and Japanese lacquer ware. (Wicks ZN, Jones FN, Pappas SP (1999) Organic coatings science and technology, 2nd edn. Wiley-Interscience, New York) See Spirit Varnish. 

For the preparation of lacquer ware, the oriental lacquer is usually applied on cedar wood, particularly from the Japanese cedar tree because it is the most warp resistant wood. One coat or two coats of primer, unprocessed urushi sap is applied followed by subsequent very thin layers (from twenty to forty layers) of processed "raw urushi" lacquer, one layer at the time every one or two days per application and curing. High relative humidity at the time of application and during curing is very critical it must be in the range from 65 to about 80%. ... 

The number of layers depends on the intended quality of the final product, each layer is cured and sanded to guarantee the smoothness of the layers. Specially prepared urushi samples are used for the preparation of high quality Japanese lacquer ware. 

Japanese lacquer trays from the Momoyama period of Japan, show the influence of the Zen culture, the simplicity of the neguro technique of applying the lacquer. Numerous items of these periods, which include trays all sorts of containers and boxes, even tea pots, sake containers, musical instruments like drums and stirrups were coated with Japanese lacquer. Figure 8 [9] shows a box from the Iate18th century and early19th century. For the decorations of such items as boxes, gold and silver flakes were incorporated when the last few layers of lacquers, but before the final topcoat, were applied. As indicated earlier, fine lacquer ware may have as many as 30-40 layers of thin coating of oriental lacquer. 

Lacquer ware originating from Okinawa and Korea, but also some Chinese lacquer ware uses a considerable amount of mother of pearl or of shells as inlay for their decoration. The regional styles may differ considerably, but are quite easily distinguishable from each other. 

In the Meiji period, the end of the 19th century, Japanese lacquer products became very fashionable world wide and the European market demanded considerable amounts of Japanese lacquer ware. A new art form was developed to satisfy the European market. 

Japanese lacquer ware is also currently very popular. It is possible to purchase very nice lacquered boxes [Figure 9] or trays [Figure 10] in department stores. 

Very valuable items of high artistic value can be obtained in special art stores where artists sell very high quality lacquer ware, of traditional but also of novel and modern styles. 

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