Lacquer is a type of hard and usually shiny coating or finish applied to materials such as wood or metal. It is most often made from resin extracted from trees and waxes and has been in use since antiquity.
147-552: Asian lacquerware , which may be called "true lacquer", are objects coated with the treated, dyed and dried sap of Toxicodendron vernicifluum or related trees, applied in several coats to a base that is usually wood. This dries to a very hard and smooth surface layer which is durable, waterproof, and attractive in feel and look. Asian lacquer is sometimes painted with pictures, inlaid with shell and other materials, or carved , as well as dusted with gold and given other further decorative treatments. In modern techniques, lacquer means
294-722: A "lacquer." The oldest lacquer tree found is from the Jōmon period in Japan, 12600 years ago. The oldest lacquerware in the world, burial ornaments which were created in 9th millennium century B.C., were unearthed at the Kakinoshima site in Hakodate , Hokkaido , Japan. Various prehistoric lacquerwares have been unearthed in China dating back to the Neolithic period and objects. The early known lacquerware
441-422: A beta particle (an electron , e ) and an electron antineutrino ( ν e ), one of the neutrons in the C nucleus changes to a proton and the C nucleus reverts to the stable (non-radioactive) isotope N . During its life, a plant or animal is in equilibrium with its surroundings by exchanging carbon either with the atmosphere or through its diet. It will, therefore, have
588-487: A black coloured lacquer. Nashiji-urushi (梨子地漆) is the transparent lacquer but mixed with gamboge to create a yellow-tinged lacquer and is especially used for the sprinkled-gold technique. These lacquers are generally used for the middle layers. Japanese lacquers of this type are generally used for the top layers and are prefixed by the word jo- (上) which means 'top (layer)'. Processed lacquers can have oil added to them to make them glossy, for example, shuai-urushi (朱合漆)
735-522: A decade. It was revised again in the early 1960s to 5,730 ± 40 years, which meant that many calculated dates in papers published prior to this were incorrect (the error in the half-life is about 3%). For consistency with these early papers, it was agreed at the 1962 Radiocarbon Conference in Cambridge (UK) to use the "Libby half-life" of 5568 years. Radiocarbon ages are still calculated using this half-life, and are known as "Conventional Radiocarbon Age". Since
882-423: A few years, but the surface waters also receive water from the deep ocean, which has more than 90% of the carbon in the reservoir. Water in the deep ocean takes about 1,000 years to circulate back through surface waters, and so the surface waters contain a combination of older water, with depleted C , and water recently at the surface, with C in equilibrium with the atmosphere. Creatures living at
1029-442: A fragment of bone, provides information that can be used to calculate when the animal or plant died. The older a sample is, the less C there is to be detected, and because the half-life of C (the period of time after which half of a given sample will have decayed) is about 5,730 years, the oldest dates that can be reliably measured by this process date to approximately 50,000 years ago (in this interval about 99.8% of
1176-408: A given sample stopped exchanging carbon – the older the sample, the less C will be left. The equation governing the decay of a radioactive isotope is: N = N 0 e − λ t {\displaystyle N=N_{0}\,e^{-\lambda t}\,} where N 0 is the number of atoms of the isotope in the original sample (at time t = 0, when
1323-400: A higher δ C than one that eats food with lower δ C values. The animal's own biochemical processes can also impact the results: for example, both bone minerals and bone collagen typically have a higher concentration of C than is found in the animal's diet, though for different biochemical reasons. The enrichment of bone C also implies that excreted material
1470-399: A long time to dry, with Japan black being the fastest drying and thus the most economical to use. The problem with using nitrocellulose in lacquers was its high viscosity, which necessitated dilution of the product with large amounts of thinner for application, leaving only a very thin film of finish not durable enough for outdoor use. This problem was overcome by decreasing the viscosity of
1617-413: A mass of less than 1% of those on land and are not shown in the diagram. Accumulated dead organic matter, of both plants and animals, exceeds the mass of the biosphere by a factor of nearly 3, and since this matter is no longer exchanging carbon with its environment, it has a C / C ratio lower than that of the biosphere. The variation in the C / C ratio in different parts of
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#17328687896261764-647: A mixture of various organic solvents . Although synthetic lacquer is more durable than shellac, traditional shellac finishes are nevertheless often preferred for their aesthetic characteristics, as with French polish , as well as their "all-natural" and generally food-safe ingredients. The English lacquer is from the archaic French word lacre , "a kind of sealing wax", from Portuguese lacre , itself an unexplained variant of Medieval Latin lacca "resinous substance," from Arabic lakk ( لك ), from Persian lāk ( لاک ), from Hindi lākh ( लाख ); Prakrit lakkha , 𑀮𑀓𑁆𑀔 ), itself from
1911-854: A paper in Science in 1947, in which the authors commented that their results implied it would be possible to date materials containing carbon of organic origin. Libby and James Arnold proceeded to test the radiocarbon dating theory by analyzing samples with known ages. For example, two samples taken from the tombs of two Egyptian kings, Zoser and Sneferu , independently dated to 2625 BC plus or minus 75 years, were dated by radiocarbon measurement to an average of 2800 BC plus or minus 250 years. These results were published in Science in December 1949. Within 11 years of their announcement, more than 20 radiocarbon dating laboratories had been set up worldwide. In 1960, Libby
2058-562: A pit grave dating from the first half of the Initial Jōmon period (approx. 9,000 years ago) Japanese lacquering technology may have been invented by the Jōmon. They learned to refine urushi (poison oak sap) – the process taking several months. Iron oxide (colcothar) and cinnabar (mercury sulfide) were used for producing red lacquer. Lacquer was used both on pottery, and on different types of wooden items. In some cases, burial clothes for
2205-530: A pit grave dating from the first half of the Initial Jōmon period. Also, at Kakinoshima "A" Excavation Site, earthenware with a spout painted with vermilion lacquer, which was made 3200 years ago, was found almost completely intact. During the Shang dynasty (1600–1046 BC), the sophisticated techniques used in the lacquer process were first developed and it became a highly artistic craft, although various prehistoric lacquerwares have been unearthed in China dating back to
2352-403: A pottery and wood coating, japanning was the popular (mostly black) coating of the accelerating metalware industry. By the twentieth century, the term was freely applied to coatings based on various varnishes and lacquers besides the traditional shellac. Lacquerware Lacquerware are objects decoratively covered with lacquer . Lacquerware includes small or large containers, tableware,
2499-456: A primer, colour coat and clear topcoat, commonly known as clear coat finishes. Due to health risks and environmental considerations involved in the use of solvent-based lacquers, much work has gone into the development of water-based lacquers. Such lacquers are considerably less toxic, more environmentally friendly, and, in many cases, produce acceptable results. While water-based lacquer's fumes are considerably less hazardous, and it does not have
2646-721: A range of clear or pigmented coatings that dry by solvent evaporation to produce a hard, durable finish. The finish can be of any sheen level from ultra matte to high gloss , and it can be further polished as required. Lacquer finishes are usually harder and more brittle than oil-based or latex paints and are typically used on hard and smooth surfaces. In terms of modern finishing products, finishes based on shellac dissolved in alcohol are often called shellac or lac to distinguish them from synthetic lacquer, often called simply lacquer , which consists of synthetic polymers (such as nitrocellulose , cellulose acetate butyrate ("CAB"), or acrylic resin ) dissolved in lacquer thinner ,
2793-554: A red or black background. Shwezawa is a distinctive form in its use of gold leaf to fill in the designs on a black background. Palace scenes, scenes from the Jataka tales, and the signs of the Burmese Zodiac are popular designs and some vessels may be encrusted with glass mosaic or semi-precious stones in gold relief. The objects are all handmade and the designs and engraving done free-hand. It may take three to four months to finish
2940-629: A sample. More recently, accelerator mass spectrometry has become the method of choice; it counts all the C atoms in the sample and not just the few that happen to decay during the measurements; it can therefore be used with much smaller samples (as small as individual plant seeds), and gives results much more quickly. The development of radiocarbon dating has had a profound impact on archaeology . In addition to permitting more accurate dating within archaeological sites than previous methods, it allows comparison of dates of events across great distances. Histories of archaeology often refer to its impact as
3087-454: A series of artistic innovations from which craftsmen producing purely utilitarian or decorative pieces would also benefit. Creating images with crushed eggshell, painting pigment over gold and tin foil and adding sand to lacquer were all techniques developed by those first students. The metallic color lacquerware for which Vietnamese craftsmen are rightly famous, was first developed by artists experimenting with many innovative techniques. After
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#17328687896263234-664: A single handle or hsun gyaink are usually plain red or black. Daunglan are low tables for meals and may be simple broad based or have three curved feet in animal or floral designs with a lid. Water carafes or yeidagaung with a cup doubling as a lid, and vases are also among lacquerware still in use in many monasteries. Various round boxes with lids, small and large, are known as yun-it including ones for paan called kun-it ( Burmese : ကွမ်းအစ် ; betel boxes). Yun titta are rectangular boxes for storing various articles including peisa or palm leaf manuscripts when they are called sadaik titta . Pedestal dishes or small trays with
3381-436: A small vessel but perhaps over a year for a larger piece. The finished product is a result of teamwork and not crafted by a single person. The most distinctive vessel is probably a rice bowl on a stem with a spired lid for monks called hsun ok . Lahpet ok is a shallow dish with a lid and has a number of compartments for serving lahpet (pickled tea) with its various accompaniments. Stackable tiffin carriers fastened with
3528-532: A stem with or without a lid are known as kalat for serving delicacies or offering flowers to royalty or the Buddha . Theatrical troupes and musicians have their lacquerware in costumes, masks, head-dresses, and musical instruments, some of them stored and carried in lacquer trunks. Boxes in the shape of a pumpkin or a bird such as the owl, which is believed to bring luck, or the hintha ( Brahminy duck ) are common too. Screens and small polygonal tables are also made for
3675-429: A variety of small objects carried by people, and larger objects such as furniture and even coffins painted with lacquer. Before lacquering, the surface is sometimes painted with pictures, inlaid with shell and other materials, or carved . The lacquer can be dusted with gold or silver and given further decorative treatments. East Asian countries have long traditions of lacquer work, going back several thousand years in
3822-624: Is a painting technique in Vietnam . It developed from the painters of the Hanoi EBAI in the 1930s and today is counted a national painting style with many famous painters. In 1924 the Ecole des Beaux Arts was established in Hanoi . This institution was to be the birthplace of the revitalised art of lacquer painting. In 1934 the school opened its lacquer department and it was from here that well known contributors to
3969-429: Is also referred to individually as a carbon exchange reservoir. The different elements of the carbon exchange reservoir vary in how much carbon they store, and in how long it takes for the C generated by cosmic rays to fully mix with them. This affects the ratio of C to C in the different reservoirs, and hence the radiocarbon ages of samples that originated in each reservoir. The atmosphere, which
4116-418: Is also used in enamel paints , which have the advantage of not needing to be buffed to obtain a shine. Enamels, however, are slow drying. The advantage of acrylic lacquer is its exceptionally fast drying time. The use of lacquers in automobile finishes was discontinued when tougher, more durable, weather- and chemical-resistant two-component polyurethane coatings were developed. The system usually consists of
4263-414: Is assumed to have originally had the same C / C ratio as the ratio in the atmosphere, and since the size of the sample is known, the total number of atoms in the sample can be calculated, yielding N 0 , the number of C atoms in the original sample. Measurement of N , the number of C atoms currently in the sample, allows the calculation of t , the age of the sample, using
4410-425: Is by spraying, and the development of nitrocellulose lacquers led to the first extensive use of spray guns. Nitrocellulose lacquers produce a hard yet flexible, durable finish that can be polished to a high sheen. Drawbacks of these lacquers include the hazardous nature of the solvent, which is flammable and toxic, and the hazards of nitrocellulose in the manufacturing process. The lacquer grade of soluble nitrocellulose
4557-546: Is called raw lacquer (生漆: ki-urushi in Japanese, shengqi in Chinese). This is directly from the tree itself with some impurities filtered out. Raw lacquer has a water content of around 25% and appears in a light brown colour. This comes in a standard grade made from Chinese lacquer, which is generally used for ground layers by mixing with a powder, and a high-quality grade made from Japanese lacquer called kijomi-urushi (生正味漆) which
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4704-455: Is closely related to the more highly nitrated form which is used to make explosives. They become relatively non-toxic after approximately a month since, at this point, the lacquer has evaporated most of the solvents used in its production. Lacquers using acrylic resin , a synthetic polymer, were developed in the 1950s. Acrylic resin is colourless, transparent thermoplastic , obtained by the polymerization of derivatives of acrylic acid . Acrylic
4851-440: Is contaminated so that 1% of the sample is modern carbon, it will appear to be 600 years younger; for a sample that is 34,000 years old, the same amount of contamination would cause an error of 4,000 years. Contamination with old carbon, with no remaining C , causes an error in the other direction independent of age – a sample contaminated with 1% old carbon will appear to be about 80 years older than it truly is, regardless of
4998-428: Is depleted in C because of the marine effect, C is removed from the southern atmosphere more quickly than in the north. The effect is strengthened by strong upwelling around Antarctica. If the carbon in freshwater is partly acquired from aged carbon, such as rocks, then the result will be a reduction in the C / C ratio in the water. For example, rivers that pass over limestone , which
5145-400: Is depleted in C relative to the diet. Since C makes up about 1% of the carbon in a sample, the C / C ratio can be accurately measured by mass spectrometry . Typical values of δ C have been found by experiment for many plants, as well as for different parts of animals such as bone collagen , but when dating a given sample it is better to determine
5292-582: Is derived from trees indigenous to East Asia, like lacquer tree Toxicodendron vernicifluum , and wax tree Toxicodendron succedaneum . The fresh resin from the T. vernicifluum trees causes urushiol-induced contact dermatitis and great care is therefore required in its use. The Chinese treated the allergic reaction with crushed shellfish, which supposedly prevents lacquer from drying properly. Lacquer skills became very highly developed in Asia, and many highly decorated pieces were produced. It has been confirmed that
5439-426: Is done by calibration curves (discussed below), which convert a measurement of C in a sample into an estimated calendar age. The calculations involve several steps and include an intermediate value called the "radiocarbon age", which is the age in "radiocarbon years" of the sample: an age quoted in radiocarbon years means that no calibration curve has been used − the calculations for radiocarbon years assume that
5586-409: Is incorporated into plants by photosynthesis ; animals then acquire C by eating the plants. When the animal or plant dies, it stops exchanging carbon with its environment, and thereafter the amount of C it contains begins to decrease as the C undergoes radioactive decay . Measuring the proportion of C in a sample from a dead plant or animal, such as a piece of wood or
5733-461: Is known as moxian (polish-reveal) in which a design is built up with lacquer in certain areas, the remaining areas are filled with lacquer of a different color, and the entire surface is polished down. Especially the art of inlaying lacquer with mother-of-pearl was intensively developed during the Song dynasty. However, during the Song, the artistic craft also made use of inlaid gold in a process of which
5880-459: Is less CO 2 available for the photosynthetic reactions. Under these conditions, fractionation is reduced, and at temperatures above 14 °C (57 °F) the δ C values are correspondingly higher, while at lower temperatures, CO 2 becomes more soluble and hence more available to marine organisms. The δ C value for animals depends on their diet. An animal that eats food with high δ C values will have
6027-528: Is mixed with linseed oil. Other specialist lacquers include ikkake-urushi (釦漆) which is thick and used mainly for applying gold or silver leaf. Solvent-based dipping lacquers that contain nitrocellulose , a resin obtained from the nitration of cotton and other cellulosic materials, debuted in the 19th century along with nitrocellulose's other commercial applications. They were used, for example, on brass items such as musical instruments. Faster-drying and more durable versions of these lacquers were developed in
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6174-415: Is mostly composed of calcium carbonate , will acquire carbonate ions. Similarly, groundwater can contain carbon derived from the rocks through which it has passed. These rocks are usually so old that they no longer contain any measurable C , so this carbon lowers the C / C ratio of the water it enters, which can lead to apparent ages of thousands of years for both the affected water and
6321-419: Is now used to convert a given measurement of radiocarbon in a sample into an estimate of the sample's calendar age. Other corrections must be made to account for the proportion of C in different types of organisms (fractionation), and the varying levels of C throughout the biosphere (reservoir effects). Additional complications come from the burning of fossil fuels such as coal and oil, and from
6468-435: Is produced throughout the Japanese archipelago, with many regional techniques and variations. Besides the very old Kamakura tradition mentioned above (and still alive today), the port town of Wajima provides a good example of regional lacquerware. Wajima-nuri , dating back to the 16th century, is characterized by use of the elm-like Japanese zelkova ( keyaki 欅), powdered earth, and delicate features formed from cloth. (See
6615-456: Is sometimes called) percolates into the rest of the reservoir. Photosynthesis is the primary process by which carbon moves from the atmosphere into living things. In photosynthetic pathways C is absorbed slightly more easily than C , which in turn is more easily absorbed than C . The differential uptake of the three carbon isotopes leads to C / C and C / C ratios in plants that differ from
6762-453: Is the main pathway by which C is created: n + 7 N → 6 C + p where n represents a neutron and p represents a proton . Once produced, the C quickly combines with the oxygen ( O ) in the atmosphere to form first carbon monoxide ( CO ), and ultimately carbon dioxide ( CO 2 ). C + O 2 → CO + O CO + OH → CO 2 + H Carbon dioxide produced in this way diffuses in
6909-399: Is the secretion of the lac bug ( Tachardia lacca Kerr. or Laccifer lacca ). It is used for wood finish, lacquerware, skin cosmetic, ornaments, dye for textiles, production of different grades of shellac for surface coating. The Atharvaveda text 1200 BCE – 1000 BCE devotes a chapter to 'lākshā' and its various uses. Barniz de Pasto ( es ) is a lacquer-like varnish technique originating in
7056-562: Is to engrave intricate patterns in the lacquer surface and to fill the intaglio with gold powder. The knowledge of the Chinese methods of the lacquer process spread from China during the Han, Tang and Song dynasties, eventually it was introduced to Korea, Japan. In Japan, the art of lacquerware-making came along with Buddhism and other cultural artifacts from China via the Korean Peninsula during
7203-447: Is used for the last finishing layers. The processed form (in which the lacquer is stirred continuously until much of the water content has evaporated) is called guangqi (光漆) in Chinese but comes under many different Japanese names depending on the variation, for example, kijiro-urushi (木地呂漆) is standard transparent lacquer sometimes used with pigments and kuroroiro-urushi (黒呂色漆) is the same but pre-mixed with iron hydroxide to produce
7350-412: Is used not only as a finish, because if mixed with ground fired and unfired clays applied to a mould with layers of hemp cloth, it can produce objects without need for another core like wood. The process is called "kanshitsu" in Japan. In the lacquering of the Chinese musical instrument, the guqin , the lacquer is mixed with deer horn powder (or ceramic powder) to give it more strength so it can stand up to
7497-565: Is usually needed to determine the size of the offset, for example by comparing the radiocarbon age of deposited freshwater shells with associated organic material. Volcanic eruptions eject large amounts of carbon into the air. The carbon is of geological origin and has no detectable C , so the C / C ratio in the vicinity of the volcano is depressed relative to surrounding areas. Dormant volcanoes can also emit aged carbon. Plants that photosynthesize this carbon also have lower C / C ratios: for example, plants in
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#17328687896267644-399: Is where C is generated, contains about 1.9% of the total carbon in the reservoirs, and the C it contains mixes in less than seven years. The ratio of C to C in the atmosphere is taken as the baseline for the other reservoirs: if another reservoir has a lower ratio of C to C , it indicates that the carbon is older and hence that either some of
7791-402: The C has decayed, or the reservoir is receiving carbon that is not at the atmospheric baseline. The ocean surface is an example: it contains 2.4% of the carbon in the exchange reservoir, but there is only about 95% as much C as would be expected if the ratio were the same as in the atmosphere. The time it takes for carbon from the atmosphere to mix with the surface ocean is only
7938-515: The C will have decayed), although special preparation methods occasionally make an accurate analysis of older samples possible. In 1960, Libby received the Nobel Prize in Chemistry for his work. Research has been ongoing since the 1960s to determine what the proportion of C in the atmosphere has been over the past 50,000 years. The resulting data, in the form of a calibration curve ,
8085-489: The C / C ratio in the atmosphere. This increase in C concentration almost exactly cancels out the decrease caused by the upwelling of water (containing old, and hence C -depleted, carbon) from the deep ocean, so that direct measurements of C radiation are similar to measurements for the rest of the biosphere. Correcting for isotopic fractionation, as is done for all radiocarbon dates to allow comparison between results from different parts of
8232-699: The chōnin class and samurai class collected inro of high aesthetic value, precisely designed with lacquer. Marie Antoinette and Maria Theresa are known collectors of Japanese lacquerware and their collections are now often exhibited in the Louvre and the Palace of Versailles . In the Meiji period (1868-1912), Richly-decorated lacquerwares in original designs were popular domestically, and even more so with Western buyers during this period of European and American fascination with Japanese art . Shibata Zeshin 's lacquer work
8379-404: The δ C value for that sample directly than to rely on the published values. The carbon exchange between atmospheric CO 2 and carbonate at the ocean surface is also subject to fractionation, with C in the atmosphere more likely than C to dissolve in the ocean. The result is an overall increase in the C / C ratio in the ocean of 1.5%, relative to
8526-536: The Neolithic period. The earliest extant Chinese lacquer object, a red wooden bowl, was unearthed at a Hemudu culture (5000–4500 BC) site in China. By the Han dynasty (206 BC – 220 AD), many centres of lacquer production became firmly established. The knowledge of the Chinese methods of the lacquer process spread from China during the Han , Tang and Song dynasties. Eventually it was introduced to Korea and Japan. Trade of lacquer objects travelled through various routes to
8673-654: The Pre-Columbian era that is a specialty of Pasto, Colombia . It is made by chewing the resin of the Andean mopa-mopa shrub ( Elaeagia pastoensis ) into thin layers, and then painting it and applying it to a wood, metal, clay or glass surface using heated stones. Historically, the technique was applied to wooden keros , drinking vessels. Known in Mexican Spanish as laca or maque (from Japanese maki-e ), Mexican lacquer has independent origins from Asian lacquer. In
8820-534: The Sanskrit word lākshā ( लाक्षा ) for lac bug , representing the number one hundred thousand (100,000), used as wood finish in ancient India and neighbouring areas. Lacquer sheen is a measurement of the shine for a given lacquer. Different manufacturers have their own names and standards for their sheen. The most common names from least shiny to most shiny are: flat, matte, eggshell, satin, semi-gloss, and gloss (high). In India shellac derived from insect lac
8967-471: The reunification , the art of lacquerware was slowly dying out in Vietnam. But since the 1980s, the government has recognized it as a vital cultural and economic force and has encouraged the business community to invest in the craft. As a result, we see a resurgence of lacquerware and a proliferation of lacquerware products from Vietnam. In India, the insect lac or shellac was used since ancient times. Shellac
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#17328687896269114-608: The "radiocarbon revolution". Radiocarbon dating has allowed key transitions in prehistory to be dated, such as the end of the last ice age , and the beginning of the Neolithic and Bronze Age in different regions. In 1939, Martin Kamen and Samuel Ruben of the Radiation Laboratory at Berkeley began experiments to determine if any of the elements common in organic matter had isotopes with half-lives long enough to be of value in biomedical research. They synthesized C using
9261-467: The 10th century, such as diaoqi ( carved lacquer ) which involves building up layers comprising thinly-applied coats of lacquer and carving it into a three-dimensional design; qiangjin (engraved gold) in which fine lines are incised, an adhesive of lacquer is applied, and gold foil or powder is pressed into the grooves; and diaotian or tianqi (filled-in) in which the lacquer is inlaid with lacquer of another color. A variation of diaotian or tianqi
9408-561: The 13th century. Evidence for older lacquerware in Bagan remains inconclusive. Bayinnaung 's conquest and subjugation in 1555–1562 of Manipur , Bhamo , Zinme ( Chiang Mai ), Linzin ( Lan Xang ), and up the Taping and Shweli rivers in the direction of Yunnan brought back large numbers of skilled craftsmen into Burma. It is thought that the finer sort of Burmese lacquerware, called Yun, was introduced during this period by imported artisans belonging to
9555-513: The 8th century, and carved lacquerware came to Japan from Ming dynasty China during the 14th century. One of the earliest Japanese techniques for decorating the lacquer surface was, besides painting simple designs, the gold and silver foil inlay of the Nara period (710–784). This technique was transmitted from China during the Tang dynasty. Coromandel lacquer is a Chinese export type, so called because it
9702-600: The Asuka and Nara periods , between the 7th and 8th centuries, Chinese lacquer art forms were imported to Japan. In the Heian period (794-1185), various Maki-e techniques characteristic of Japanese lacquerware were developed. While the method of drawing designs with a brush by dissolving gold powder in lacquer is a common technique in other countries, the method of drawing designs with lacquer and then sprinkling gold, silver, or copper powder of various sizes and shapes on top to polish them
9849-406: The Chinese or Japanese lacquer. Burmese lacquer sets slower, and is painted by craftsmen's hands without using brushes. Raw lacquer can be "coloured" by the addition of small amounts of iron oxides , giving red or black depending on the oxide. There is some evidence that its use is even older than 8,000 years from archaeological digs in Japan and China. Later, pigments were added to make colours. It
9996-471: The Han dynasty. In the Tang dynasty (618–907), Chinese lacquerware saw a new style marked by the use of sheets of gold or silver made in various shapes, such as birds, animals, and flowers. The cut-outs were affixed onto the surface of the lacquerware, after which new layers of lacquer were applied, dried, and then ground away, so the surface could be polished to reveal the golden or silvery patterns beneath. This
10143-535: The Japanese article, 輪島塗 . A more complete list of regional lacquer traditions is available in the Japanese article .) Ryukyuan lacquerware is one of the chief artistic products of the Ryukyu Islands (today Okinawa Prefecture of Japan ); it is quite distinct from the lacquerware found among the surrounding cultures. Nevertheless, Chinese and Japanese influences are present. Yun-de is lacquerware in Burmese , and
10290-469: The Middle East. Known applications of lacquer in China included coffins, music instruments, furniture, and various household items. Lacquer mixed with powdered cinnabar is used to produce the traditional red lacquerware from China. From the 16th century to the 17th century, lacquer was introduced to Europe on a large scale for the first time through trade with Japanese . Until the 19th century, lacquerware
10437-990: The Ming dynasty made a trip to Japan to study Japanese techniques, and a Japanese visited a Chinese imperial workshop in Beijing during the Ming dynasty. It is well documented that the Yongzheng Emperor had a formidable interest in Japanese lacquer, yangqi , and this was reflected in many of the works produced in the Imperial workshops during his reign. In the Azuchi-Momoyama period (1568-1600) also made its way into Colonial Mexico ( Manila Galleons ) and Europe by Nanban trade . Japanese lacquerware attracted European aristocrats and missionaries from Europe, and western style chests and church furniture were exported in response to their requests. The Edo period (1603–1868) saw an increase in
10584-545: The Netherlands, and Spain in the 17th century, the Europeans developed imitation techniques. The European technique, which is used on furniture and other objects, uses finishes that have a resin base similar to shellac. The technique, which became known as japanning, involves applying several coats of varnish which are each heat-dried and polished. In the 18th century, japanning gained a large popular following. Although traditionally
10731-575: The UK, Herbert Austin were introducing nitrocellulose lacquers at the same time, and soon the market flourished. Nitrocellulose lacquers are also used to make firework fuses waterproof. The nitrocellulose and other resins and plasticizers are dissolved in the solvent, and each coat of lacquer dissolves some of the previous coat. These lacquers were a huge improvement over earlier automobile and furniture finishes, both in ease of application and in colour retention. The preferred method of applying quick-drying lacquers
10878-559: The Yun or Northern Thai people of the Chiang Mai region. Lacquer vessels, boxes and trays have a coiled or woven bamboo-strip base often mixed with horsehair. The thitsee may be mixed with ashes or sawdust to form a putty-like substance called thayo which can be sculpted. The object is coated layer upon layer with thitsee and thayo to make a smooth surface, polished and engraved with intricate designs, commonly using red, green and yellow colors on
11025-399: The above-ground nuclear tests performed in the 1950s and 1960s. Because the time it takes to convert biological materials to fossil fuels is substantially longer than the time it takes for its C to decay below detectable levels, fossil fuels contain almost no C . As a result, beginning in the late 19th century, there was a noticeable drop in the proportion of C in
11172-399: The actual calendar date, both because it uses the wrong value for the half-life of C , and because no correction (calibration) has been applied for the historical variation of C in the atmosphere over time. Carbon is distributed throughout the atmosphere, the biosphere, and the oceans; these are referred to collectively as the carbon exchange reservoir, and each component
11319-455: The ancient temples of Bagan. At the village of Kyaukka near Monywa in the Chindwin valley, however, sturdy lacquer utensils are still produced for everyday use mainly in plain black. A decline in the number of visitors combined with the cost of resin, which has seen a 40-fold rise in 15 years, has led to the closure of over two-thirds of more than 200 lacquerware workshops in Bagan. Sơn mài
11466-418: The appropriate correction for the location of their samples. The effect also applies to marine organisms such as shells, and marine mammals such as whales and seals, which have radiocarbon ages that appear to be hundreds of years old. The northern and southern hemispheres have atmospheric circulation systems that are sufficiently independent of each other that there is a noticeable time lag in mixing between
11613-453: The art export market, promoting Japan's lacquers and other decorative arts at a succession of world's fairs . Lacquer from Japanese workshops was recognised as technically superior to what could be produced anywhere else in the world. Today, the Japanese government has designated excellent lacquer artists as Living National Treasures and is encouraging them to make lacquerware. Lacquerware
11760-461: The art including; Bui Trang Chuoc, Nguyen Van Binh, Nguyen Khang, Nguyen Duc Nung, Nguyen Tien Chung, and Pham Van Don would emerge. It was the first generation of Vietnamese students of the Indochina School of Fine Art during the 1930s, who elevated the craft of lacquer painting to a truly fine art. Less interested in decor than their craftsmen predecessors, it was also these men who would begin
11907-545: The art is called Pan yun ( ပန်းယွန်း ). The lacquer is the sap tapped from the varnish tree or Thitsee ( Gluta usitata , syn. Melanorrhoea usitata ) that grows wild in the forests of Myanmar (formerly Burma). It is straw-colored but turns black on exposure to air. When brushed in or coated on, it forms a hard glossy smooth surface resistant to a degree from the effects of exposure to moisture or heat. The earliest fragments of lacquerware basketry found in Bagan dates back to
12054-457: The atmosphere as the carbon dioxide generated from burning fossil fuels began to accumulate. Conversely, nuclear testing increased the amount of C in the atmosphere, which reached a maximum in about 1965 of almost double the amount present in the atmosphere prior to nuclear testing. Measurement of radiocarbon was originally done with beta-counting devices, which counted the amount of beta radiation emitted by decaying C atoms in
12201-438: The atmosphere might be expected to decrease over thousands of years, but C is constantly being produced in the lower stratosphere and upper troposphere , primarily by galactic cosmic rays , and to a lesser degree by solar cosmic rays. These cosmic rays generate neutrons as they travel through the atmosphere which can strike nitrogen-14 ( N ) atoms and turn them into C . The following nuclear reaction
12348-547: The atmosphere, is dissolved in the ocean, and is taken up by plants via photosynthesis . Animals eat the plants, and ultimately the radiocarbon is distributed throughout the biosphere . The ratio of C to C is approximately 1.25 parts of C to 10 parts of C . In addition, about 1% of the carbon atoms are of the stable isotope C . The equation for the radioactive decay of C is: 6 C → 7 N + e + ν e By emitting
12495-421: The atmospheric C / C ratio has not changed over time. Calculating radiocarbon ages also requires the value of the half-life for C . In Libby's 1949 paper he used a value of 5720 ± 47 years, based on research by Engelkemeir et al. This was remarkably close to the modern value, but shortly afterwards the accepted value was revised to 5568 ± 30 years, and this value was in use for more than
12642-430: The automobile and other similar industrial applications. Water-based lacquers are used extensively in wood furniture finishing as well. One drawback of water-based lacquer is that it has a tendency to be highly reactive to other fresh finishes such as quick-dry primer (excluding waterborne lacquer primers), caulking and even some paints that have a paint/primer aspect. Tannin bleed-through can also be an issue, depending on
12789-425: The biosphere, gives an apparent age of about 400 years for ocean surface water. Libby's original exchange reservoir hypothesis assumed that the C / C ratio in the exchange reservoir is constant all over the world, but it has since been discovered that there are several causes of variation in the ratio across the reservoir. The CO 2 in the atmosphere transfers to the ocean by dissolving in
12936-520: The black base of lacquerware, and the entire lacquerware is covered with shiny gold and silver grains. Primitive lacquer was used in Japan as early as 12,600 BC, during the Jōmon period . Lacquer was used in Japan as early as 7000 BCE, during the Jōmon period . Evidence for the earliest lacquerware was discovered at the Kakinoshima "B" Excavation Site in Hokkaido . These objects were discovered in
13083-530: The brand of lacquer used. Once it happens, there is no easy fix as the lacquer is so reactive to other products. Water-based lacquer used for wood finishing is also not rated for exterior wear, unless otherwise specified. Just as china is a common name for porcelain , japanning is an old name to describe the European technique to imitate Asian lacquerware . As Asian lacquer work became popular in England, France,
13230-450: The calibration curve (IntCal) also reports past atmospheric C concentration using this conventional age, any conventional ages calibrated against the IntCal curve will produce a correct calibrated age. When a date is quoted, the reader should be aware that if it is an uncalibrated date (a term used for dates given in radiocarbon years) it may differ substantially from the best estimate of
13377-435: The carbon exchange reservoir means that a straightforward calculation of the age of a sample based on the amount of C it contains will often give an incorrect result. There are several other possible sources of error that need to be considered. The errors are of four general types: In the early years of using the technique, it was understood that it depended on the atmospheric C / C ratio having remained
13524-500: The carbon exchange reservoir, but because of the long delay in mixing with the deep ocean, the actual effect is a 3% reduction. A much larger effect comes from above-ground nuclear testing, which released large numbers of neutrons into the atmosphere, resulting in the creation of C . From about 1950 until 1963, when atmospheric nuclear testing was banned , it is estimated that several tonnes of C were created. If all this extra C had immediately been spread across
13671-734: The cases of China, Japan and Korea. The best known lacquer, an urushiol -based lacquer common in East Asia, is obtained from the dried sap of Toxicodendron vernicifluum . Other types of lacquers are processed from a variety of plants and insects. The traditions of lacquer work in Southeast Asia , South Asia and the Americas are also ancient and originated independently. True lacquer is not made outside Asia, but some imitations, such as Japanning in Europe, or parallel techniques, are often loosely referred to
13818-406: The combustibility issues of solvent-based lacquers, the product still dries fairly quickly. Even though its odor is weaker, water-based lacquers can still produce airborne particulates that can get into the lungs, so proper protective wear still needs to be worn. More and more water-based colored lacquers are replacing solvent-based clear and colored lacquers in under-hood and interior applications in
13965-435: The date of the sample. Samples for dating need to be converted into a form suitable for measuring the C content; this can mean conversion to gaseous, liquid, or solid form, depending on the measurement technique to be used. Before this can be done, the sample must be treated to remove any contamination and any unwanted constituents. This includes removing visible contaminants, such as rootlets that may have penetrated
14112-502: The dead were also lacquered. Many lacquered objects have turned up during the Early Jōmon period; this indicates that this was an established part of Jōmon culture. Experts are divided on whether Jōmon lacquer was derived from Chinese techniques, or invented independently. For example, Mark Hudson believes that “Jomon lacquer technology was developed independently in Japan rather than being introduced from China as once believed”. During
14259-421: The earliest era from which notable quantities of lacquerware have survived, with states, later kingdoms, of Qin and Chu producing the largest number of lacquerware. The state of Chu having the geographical advantage and warmer climates enabled dedicated mass cultivation of lacquer trees and for lacquerware to become a commercial industry. Because of this, Chu-state became famous for its lacquerware exports in
14406-496: The early 1920s, when the end of the WWI caused a massive overcapacity of nitrocellulose production, and soon greatly displaced much use of the slower-drying paints and lacquers that preceded them; they were extensively used in the automotive industry and others for the next 30 years until further chemical advancements replaced them. Prior to their introduction, mass-produced automotive finishes were limited in colour, damaged easily, and took
14553-490: The early 20th century hence gives an apparent date older than the true date. For the same reason, C concentrations in the neighbourhood of large cities are lower than the atmospheric average. This fossil fuel effect (also known as the Suess effect, after Hans Suess, who first reported it in 1955) would only amount to a reduction of 0.2% in C activity if the additional carbon from fossil fuels were distributed throughout
14700-401: The entire carbon exchange reservoir, it would have led to an increase in the C / C ratio of only a few per cent, but the immediate effect was to almost double the amount of C in the atmosphere, with the peak level occurring in 1964 for the northern hemisphere, and in 1966 for the southern hemisphere. The level has since dropped, as this bomb pulse or "bomb carbon" (as it
14847-424: The equation above. The half-life of a radioactive isotope (usually denoted by t 1/2 ) is a more familiar concept than the mean-life, so although the equations above are expressed in terms of the mean-life, it is more usual to quote the value of C 's half-life than its mean-life. The currently accepted value for the half-life of C is 5,700 ± 30 years. This means that after 5,700 years, only half of
14994-468: The errors caused by the variation over time in the C / C ratio. These curves are described in more detail below . Coal and oil began to be burned in large quantities during the 19th century. Both are sufficiently old that they contain little or no detectable C and, as a result, the CO 2 released substantially diluted the atmospheric C / C ratio. Dating an object from
15141-684: The fingering. There are a number of forms of urushiol. They vary by the length of the R chain, which depends on the species of plant producing the urushiol. Urushiol can also vary in the degree of saturation in the carbon chain. Urushiol can be drawn as follows: [REDACTED] , where: R = (CH 2 ) 14 CH 3 or R = (CH 2 ) 7 CH=CH(CH 2 ) 5 CH 3 or R = (CH 2 ) 7 CH=CHCH 2 CH=CH(CH 2 ) 2 CH 3 or R = (CH 2 ) 7 CH=CHCH 2 CH=CHCH=CHCH 3 or R = (CH 2 ) 7 CH=CHCH 2 CH=CHCH 2 CH=CH 2 Types of lacquer vary from place to place but they can be divided into unprocessed and processed categories. The basic unprocessed lacquer
15288-551: The focused cultivation of lacquer trees and the development of the techniques used. In the 18th century colored lacquers came into wider use. With the development of economy and culture, the artistic quality of lacquered furniture has improved. Hon'ami Kōetsu and Ogata Kōrin brought the designs of the Rinpa school of painting into lacquerware. From the middle of the Edo period, inro became popular as men's accessories, and wealthy merchants of
15435-908: The former is much easier to measure, and the latter can be easily derived: the depletion of C relative to C is proportional to the difference in the atomic masses of the two isotopes, so the depletion for C is twice the depletion of C . The fractionation of C , known as δ C , is calculated as follows: δ C 13 = ( ( C 13 C 12 ) sample ( C 13 C 12 ) standard − 1 ) × 1000 {\displaystyle \delta {\ce {^{13}C}}=\left({\frac {\left({\frac {{\ce {^{13}C}}}{{\ce {^{12}C}}}}\right)_{\text{sample}}}{\left({\frac {{\ce {^{13}C}}}{{\ce {^{12}C}}}}\right)_{\text{standard}}}}-1\right)\times 1000} ‰ where
15582-463: The humidifying rooms used in production of lacquered wares. The term " Japanning " in the 17th century is a term for the technique used by Europe to emulate Asian lacquer, derived from the then famous Japanese lacquer. The general characteristic of Japanese lacquerware is the widespread use of various Maki-e techniques compared to other countries. As a result, there are many works in which relatively vivid gold and silver patterns and pictures shine on
15729-454: The initial C will remain; a quarter will remain after 11,400 years; an eighth after 17,100 years; and so on. The above calculations make several assumptions, such as that the level of C in the atmosphere has remained constant over time. In fact, the level of C in the atmosphere has varied significantly and as a result, the values provided by the equation above have to be corrected by using data from other sources. This
15876-404: The inner tree rings do not get their C replenished and instead only lose C through radioactive decay. Hence each ring preserves a record of the atmospheric C / C ratio of the year it grew in. Carbon-dating the wood from the tree rings themselves provides the check needed on the atmospheric C / C ratio: with a sample of known date, and a measurement of
16023-659: The laboratory's cyclotron accelerator and soon discovered that the atom's half-life was far longer than had been previously thought. This was followed by a prediction by Serge A. Korff , then employed at the Franklin Institute in Philadelphia , that the interaction of thermal neutrons with N in the upper atmosphere would create C . It had previously been thought that C would be more likely to be created by deuterons interacting with C . At some time during World War II, Willard Libby , who
16170-563: The lacquer tree has existed in Japan since nearly 12,600 years ago in the incipient Jōmon period . This was confirmed by radioactive carbon dating of the lacquer tree found at the Torihama shell mound and is the oldest lacquer tree in the world found as of 2011. Lacquer was used in Japan as early as 7000 BCE, during the Jōmon period. Evidence for the earliest lacquerware was discovered at the Kakinoshima "B" Excavation Site in Hokkaido . The ornaments woven with lacquered red thread were discovered in
16317-502: The neighbourhood of the Furnas caldera in the Azores were found to have apparent ages that ranged from 250 years to 3320 years. Any addition of carbon to a sample of a different age will cause the measured date to be inaccurate. Contamination with modern carbon causes a sample to appear to be younger than it really is: the effect is greater for older samples. If a sample that is 17,000 years old
16464-531: The neighbouring states in the Zhou kingdom , with literary references found in books like Zhuangzi and Shangshu , and providing some cultural cross-pollination between the southern culture of Chu and the culture of Zhongyuan . At the time of the Han dynasty (206 BC – 220 AD), special administrations were established to organize and divide labor for the expanding lacquer production in China. Elaborate incised decorations were used in lacquerware during
16611-420: The ocean surface have the same C ratios as the water they live in, and as a result of the reduced C / C ratio, the radiocarbon age of marine life is typically about 400 years. Organisms on land are in closer equilibrium with the atmosphere and have the same C / C ratio as the atmosphere. These organisms contain about 1.3% of the carbon in the reservoir; sea organisms have
16758-635: The organism from which the sample was taken died), and N is the number of atoms left after time t . λ is a constant that depends on the particular isotope; for a given isotope it is equal to the reciprocal of the mean-life – i.e. the average or expected time a given atom will survive before undergoing radioactive decay. The mean-life, denoted by τ , of C is 8,267 years, so the equation above can be rewritten as: t = ln ( N 0 / N ) ⋅ 8267 years {\displaystyle t=\ln(N_{0}/N)\cdot {\text{8267 years}}} The sample
16905-440: The plants and freshwater organisms that live in it. This is known as the hard water effect because it is often associated with calcium ions, which are characteristic of hard water; other sources of carbon such as humus can produce similar results, and can also reduce the apparent age if they are of more recent origin than the sample. The effect varies greatly and there is no general offset that can be applied; additional research
17052-409: The polymer (the term actually post-dates the empirical solution, with Staudinger 's modern structural theory explaining polymer solution viscosity by length of molecular chains not yet experimentally proven in 1920s) with heat treatments, either with 2% of mineral acid or in an autoclave at considerable pressure. The first practical nitrocellulose enamel Glossy White S.2567, still for interior use,
17199-516: The pre-Hispanic period, a substance from the larvae of aje scale insects and/or oil from the chia seed were mixed with powdered minerals to create protective coatings and decorative designs. During this period, the process was almost always applied to dried gourds, especially to make the cups that Mesoamerican nobility drank chocolate from. After the Conquest , the Spanish had indigenous craftsmen apply
17346-413: The pre-existing Egyptian chronology nor the new radiocarbon dating method could be assumed to be accurate, but a third possibility was that the C / C ratio had changed over time. The question was resolved by the study of tree rings : comparison of overlapping series of tree rings allowed the construction of a continuous sequence of tree-ring data that spanned 8,000 years. (Since that time
17493-520: The properties of radiocarbon , a radioactive isotope of carbon . The method was developed in the late 1940s at the University of Chicago by Willard Libby , based on the constant creation of radiocarbon ( C ) in the Earth's atmosphere by the interaction of cosmic rays with atmospheric nitrogen . The resulting C combines with atmospheric oxygen to form radioactive carbon dioxide , which
17640-405: The ratios in the atmosphere. This effect is known as isotopic fractionation. To determine the degree of fractionation that takes place in a given plant, the amounts of both C and C isotopes are measured, and the resulting C / C ratio is then compared to a standard ratio known as PDB. The C / C ratio is used instead of C / C because
17787-472: The resin is urushiol, a mixture of various phenols suspended in water, plus a few proteins. In order for it to set properly it requires a humid and warm environment. The phenols oxidize and polymerize under the action of laccase enzymes, yielding a substrate that, upon proper evaporation of its water content, is hard. These lacquers produce very hard, durable finishes that are both beautiful and very resistant to damage by water, acid, alkali or abrasion. The resin
17934-463: The resin. It sets by a process called "aqua-polymerization", absorbing oxygen to set; placing in a humid environment allows it to absorb more oxygen from the evaporation of the water. Lacquer-yielding trees in Thailand, Vietnam, Burma and Taiwan, called Thitsi , are slightly different; they do not contain urushiol, but similar substances called laccol or thitsiol . The result is similar but softer than
18081-415: The same over the preceding few thousand years. To verify the accuracy of the method, several artefacts that were datable by other techniques were tested; the results of the testing were in reasonable agreement with the true ages of the objects. Over time, however, discrepancies began to appear between the known chronology for the oldest Egyptian dynasties and the radiocarbon dates of Egyptian artefacts. Neither
18228-456: The same proportion of C as the atmosphere, or in the case of marine animals or plants, with the ocean. Once it dies, it ceases to acquire C , but the C within its biological material at that time will continue to decay, and so the ratio of C to C in its remains will gradually decrease. Because C decays at a known rate, the proportion of radiocarbon can be used to determine how long it has been since
18375-412: The sample since its burial. Alkali and acid washes can be used to remove humic acid and carbonate contamination, but care has to be taken to avoid removing the part of the sample that contains the carbon to be tested. Particularly for older samples, it may be useful to enrich the amount of C in the sample before testing. This can be done with a thermal diffusion column. The process takes about
18522-502: The state of Guerrero, Uruapan and Pátzcuaro in Michoacán and Chiapa de Corzo in Chiapas. The most popular modern lacquerware are small boxes, sometimes known as cajitas de Olinalá . Radioactive carbon dating Radiocarbon dating (also referred to as carbon dating or carbon-14 dating ) is a method for determining the age of an object containing organic material by using
18669-401: The surface water as carbonate and bicarbonate ions; at the same time the carbonate ions in the water are returning to the air as CO 2 . This exchange process brings C from the atmosphere into the surface waters of the ocean, but the C thus introduced takes a long time to percolate through the entire volume of the ocean. The deepest parts of the ocean mix very slowly with
18816-590: The surface waters, and as a result water from some deep ocean areas has an apparent radiocarbon age of several thousand years. Upwelling mixes this "old" water with the surface water, giving the surface water an apparent age of about several hundred years (after correcting for fractionation). This effect is not uniform – the average effect is about 400 years, but there are local deviations of several hundred years for areas that are geographically close to each other. These deviations can be accounted for in calibration, and users of software such as CALIB can provide as an input
18963-422: The surface waters, and the mixing is uneven. The main mechanism that brings deep water to the surface is upwelling, which is more common in regions closer to the equator. Upwelling is also influenced by factors such as the topography of the local ocean bottom and coastlines, the climate, and wind patterns. Overall, the mixing of deep and surface waters takes far longer than the mixing of atmospheric CO 2 with
19110-452: The technique to European style furniture and other items, changing the decorative motifs and color schemes, but the process and materials remained mostly the same. Asian lacquerware and artisans brought by the Nao de China also had an influence on the style and motifs of colonial Mexican lacquerware. Today, workshops creating lacquerware are limited to Olinalá , Temalacatzingo and Acapetlahuaya in
19257-431: The tourist trade today. Bagan is the major centre for the lacquerware industry where the handicraft has been established for nearly two centuries, and still practiced in the traditional manner. Here a government school of lacquerware was founded in the 1920s. Since plastics, porcelain and metal have superseded lacquer in most everyday utensils, it is today manufactured in large workshops mainly for tourists who come to see
19404-478: The tree-ring data series has been extended to 13,900 years.) In the 1960s, Hans Suess was able to use the tree-ring sequence to show that the dates derived from radiocarbon were consistent with the dates assigned by Egyptologists. This was possible because although annual plants, such as corn, have a C / C ratio that reflects the atmospheric ratio at the time they were growing, trees only add material to their outermost tree ring in any given year, while
19551-404: The two. The atmospheric C / C ratio is lower in the southern hemisphere, with an apparent additional age of about 40 years for radiocarbon results from the south as compared to the north. This is because the greater surface area of ocean in the southern hemisphere means that there is more carbon exchanged between the ocean and the atmosphere than in the north. Since the surface ocean
19698-434: The value of N (the number of atoms of C remaining in the sample), the carbon-dating equation allows the calculation of N 0 – the number of atoms of C in the sample at the time the tree ring was formed – and hence the C / C ratio in the atmosphere at that time. Equipped with the results of carbon-dating the tree rings, it became possible to construct calibration curves designed to correct
19845-494: The ‰ sign indicates parts per thousand . Because the PDB standard contains an unusually high proportion of C , most measured δ C values are negative. For marine organisms, the details of the photosynthesis reactions are less well understood, and the δ C values for marine photosynthetic organisms are dependent on temperature. At higher temperatures, CO 2 has poor solubility in water, which means there
19992-456: Was abundantly exported to China where the Ming and Qing rulers generally described Japanese lacquerwares as " foreign lacquer " ( yangqi ). Yang Ming, and famous lacquer man Zhejiang , made annotations for A Record of Decoration with Lacquer, ... People of the Ming dynasty once recorded: “The decoration art with lacquer coated with gold originated (maki-e) from Japan". Yang in the reign of Xuande of
20139-411: Was awarded the Nobel Prize in Chemistry for this work. In nature, carbon exists as three isotopes . Carbon-12 ( C ) and carbon-13 ( C ) are stable and nonradioactive; carbon-14 ( C ), also known as "radiocarbon", is radioactive. The half-life of C (the time it takes for half of a given amount of C to decay ) is about 5,730 years, so its concentration in
20286-500: Was developed in Japan. This made it possible to make the gold and silver of lacquerware brighter than before. In the Kamakura period (1185–1333), carved lacquer from the Song dynasty of China was imported to Japan. However, many Japanese lacquer craftsmen did not adopt the Chinese method of depositing lacquer and then carving it; instead, they created Kamakurabori , a method of carving wood and then coating lacquer. Japanese lacquerware
20433-462: Was done by a technique known as pingtuo . Such techniques were time-consuming and costly, but these lacquerware were considered highly refined. It was also the period when the earliest practice of carving lacquerware began. The art of inlaid gold, silver, and mother-of-pearl continued from the Tang into the Song dynasty (960–1279). Several existing decorative techniques gradually developed further after
20580-503: Was especially popular. In addition, lacquerware called Shibayama , which was created in the Edo period, became popular for its showy style, inlaid with gold, silver, shellfish, ivory, coral, tortoise shell and ceramics, and reached its peak during this period. Lacquerware called Somada , which was created in the Edo period and characterized by regular patterns of finely cut seashells, gold leaf and silver leaf, also became popular during this period. The government took an active interest in
20727-545: Was introduced during the Shilla period (668 A.D. – 935 A.D.). The Goryeo dynasty (918–1392), considered the golden period of this craft, was influenced by Buddhism. The term for lacquer is urushi (漆), source of the English hybrid word " urushiol ". Etymologically, urushi may be related to the words uruwashii ("beautiful") or uruoi ("watered", "profitable", "favored"), due speculatively to their value or shiny appearance, or perhaps
20874-499: Was introduced in 1919 in the UK by Nobel Explosives . In 1923, General Motors' Oakland brand automobile was the first to introduce one of the new fast-drying nitrocellulose lacquers, a bright blue, produced by DuPont under their Duco tradename. In 1924 the other GM makes followed suit, and by 1925 nitrocellulose lacquers were thoroughly disrupting the traditional paint business for automobiles, appliances, furniture, musical instruments, caskets, and other products. Henry Ford and, in
21021-505: Was one of Japan's major exports, and European royalty, aristocrats and religious people represented by Marie-Antoinette , Maria Theresa and The Society of Jesus collected Japanese lacquerware luxuriously decorated with maki-e . The terms related to lacquer such as " Japanning ", "Urushiol" and " maque " which means lacquer in Mexican Spanish, are derived from Japanese. The trees must be at least ten years old before cutting to bleed
21168-456: Was shipped to European markets via the Coromandel coast of India. The very term 'Najeonchilgi' is a combination of two particular words: 'najeon'– mother-of-pearl and ‘chilgi’ which refers to lacquerware. ‘najeon’ refers to the composite material which forms the inner shiny shell layer. The Three Kingdom period (57 B.C. – 668 A.D.) witnessed the introduction of the first method and the second one
21315-780: Was then at Berkeley, learned of Korff's research and conceived the idea that it might be possible to use radiocarbon for dating. In 1945, Libby moved to the University of Chicago , where he began his work on radiocarbon dating. He published a paper in 1946 in which he proposed that the carbon in living matter might include C as well as non-radioactive carbon. Libby and several collaborators proceeded to experiment with methane collected from sewage works in Baltimore, and after isotopically enriching their samples they were able to demonstrate that they contained C . By contrast, methane created from petroleum showed no radiocarbon activity because of its age. The results were summarized in
21462-503: Was thought to be a red wooden bowl, which was unearthed at a Hemudu culture ( c. 5th millennium BC ) site in Zhejiang , China. During the Shang dynasty (ca. 1600–1046 BC) of China, sophisticated lacquer process techniques developed became a highly artistic craft. During the Eastern Zhou period (771–256 BC), lacquerware began appearing in large quantity. This is
21609-442: Was used since ancient times. Shellac is the secretion of the lac bug ( Tachardia lacca Kerr. or Laccifer lacca ). It is used for wood finish, lacquerware, skin cosmetic, ornaments, dye for textiles, production of different grades of shellac for surface coating. Urushiol -based lacquers differ from most others, being slow-drying, and set by oxidation and polymerization , rather than by evaporation alone. The active ingredient of
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