The term lacquer is used for a number of hard and potentially shiny finishes applied to materials such as wood. These fall into a number of very different groups.
The term lacquer originates from the Sanskrit word lākshā (लाक्षा) representing the number 100,000, which was used for both the lac insect (because of their enormous number) and the scarlet resinous secretion, rich in shellac, that it produces that was used as wood finish in ancient India and neighbouring areas.
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 to feel and look at. 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 a range of clear or coloured wood finishes that dry by solvent evaporation or a curing process that produces 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. It is also used for "lacquer paint", which is a paint that typically dries better on a hard and smooth surface.
In terms of modern products for coating finishes, lac-based finishes are likely to be referred to as shellac, while lacquer often refers to other polymers dissolved in volatile organic compounds (VOCs), such as nitrocellulose, and later acrylic compounds dissolved in lacquer thinner, a mixture of several solvents typically containing butyl acetate and xylene or toluene. Lacquer is more durable than shellac.
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, from Persian lak, from Hindi lakh (Prakrit lakkha). These ultimately derive from Sanskrit lākshā (लाक्षा), which was used for both the Lac insect and the scarlet resinous secretion it produces that was used as wood finish. Lac resin was once imported in sizeable quantity into Europe from India along with Eastern woods.
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, egg shell, satin, semi-gloss, and gloss (high).
In India the insect lac, or shellac was used since ancient times. Shellac is the secretion of the lac bug (Tachardia lacca Kerr. or Laccifer lacca). It is used for the production of a red dye and pigment (red lake), and for the production of different grades of shellac, used in surface coating.
Urushiol-based lacquers differ from most others, being slow-drying, and set by oxidation and polymerization, rather than by evaporation alone. In order for it to set properly it requires a humid and warm environment. The phenols oxidize and polymerize under the action of an enzyme laccase, 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 active ingredient of the resin is urushiol, a mixture of various phenols suspended in water, plus a few proteins. The resin 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 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.
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 the Neolithic period and objects with lacquer coating in Japan from the late Jōmon period. The earliest extant 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, Japan, Southeast and South Asia.
Trade of lacquer objects travelled through various routes to 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.
The trees must be at least ten years old before cutting to bleed 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 end result is similar but softer than 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 China. Later, pigments were added to make colours. It is used not only as a finish, but 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. Advanced decorative techniques using additional materials such as gold and silver powders and flakes ("makie") were refined to very high standards in Japan also after having been introduced from China. 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 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:
R = (CH2)14CH3 or
R = (CH2)7CH=CH(CH2)5CH3 or
R = (CH2)7CH=CHCH2CH=CH(CH2)2CH3 or
R = (CH2)7CH=CHCH2CH=CHCH=CHCH3 or
R = (CH2)7CH=CHCH2CH=CHCH2CH=CH2
Types of lacquer vary from place to place but they can be divided into unprocessed and processed categories.
The basic unprocessed lacquer 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 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 roiro-urushi (黒呂色漆) is the same but pre-mixed with iron hydroxide to produce 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) 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 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 the early 1920s 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 a long time to dry,:295–301 with Japan black being the fastest drying and thus the most economical to use. 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.:295–301 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.:295–301
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 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. Lacquer grade of soluble nitrocellulose 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 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 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 and 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 the combustibility issues of solvent based lacquers, the product still dries fairly quickly. Even though its odor is weaker, water-based lacquer 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 the automobile and other similar industrial applications. Water based lacquers are used extensively in wood furniture finishing as well.
One drawback of the 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 the brand of lacquer used. Once it happens, there is no easy fix as the lacquer is so reactive to other products. It is best when planning to spray a white based lacquer over raw wood to source and find a primer that will seal in the tannin. Some painters will use a clear to seal, but several light and fast drying coats must be applied to ensure a good seal. It is then recommended to wait until the next day to start spraying the color so the clear has time to harden and keep the white from pulling the tannin right through the clear.
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, 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 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.
... The word lacquer derives, in fact, from the Sanskrit 'Laksha' and has the same meaning as the Hindi word 'Lakh' which signifies one-hundred thousand ... enormous number of those parasitical insects which infest the plants Acacia catecu, Ficus and Butea frondosa ... great quantity of reddish colored resinous substance ... used in ancient times in India and other parts of Asia ...
... Shellac, a natural resin secreted by the scaly lac insect, has been used in India for centuries as a decorative coating for surfaces. The word lacquer in English is derived from the Sanskrit word laksha. which means one hundred thousand ...
... Along with valuable woods from the East, the ancients imported lac, a resinous incrustation produced on certain trees by the puncture of the lac insect. In India, lac was used as sealing wax, dye and varnish ... Sanskrit, laksha; Hindi, lakh; Persian, lak; Latin, lacca. The Western word 'lacquer' is derived from this term ...
... The word 'lacquer' itself stems from the term 'Laksha', from the pre-Christian, sacred Indian language Sanskrit, and originally referred to shellac, a resin produced by special insects ('lac insects') from the sap of an Indian fig tree ...
An acetate disc is a type of phonograph (gramophone) record, a mechanical sound storage medium, widely used from the 1930s to the late 1950s for recording and broadcast purposes and still in limited use today.They are also known as a test acetate, dubplate (a term from Jamaican reggae culture, now also applied to individually recorded discs of solid plastic), lacquer (a technically correct term preferred by engineers in the recording industry), transcription disc (a special recording intended for, or made from, a radio broadcast) or instantaneous disc (because it can be played immediately after recording without any further processing),
Unlike ordinary vinyl records, which are quickly formed from lumps of plastic by a mass-production molding process, a so-called acetate disc is created by using a recording lathe to cut an audio-signal-modulated groove into the surface of a special lacquer-coated blank disc, a real-time operation requiring expensive, delicate equipment and expert skill for good results. They are made for special purposes, almost never for sale to the general public. They can be played on any normal record player but will suffer from wear more quickly than vinyl. Some acetates are highly prized for their rarity, especially when they contain unpublished material.
Acetates are usually made by dubbing from a master recording in another medium, such as magnetic tape. In the vinyl record manufacturing process, an acetate master disc is cut and electroforming is used to make negative metal molds from it; each mold, known as a stamper, can be used to press thousands of vinyl copies of the master. Within the vinyl record industry, acetates are also used for evaluating the quality of the tape-to-disc transfer. They were once a favored medium for comparing different takes or mixes of a recording, and if pressed vinyl copies of an impending new release were not yet available, acetates were used for getting preview copies into the hands of important radio disc jockeys.
Acetates were produced in very small quantities using elementary cutting machines. Majority of discs found on the market were not labelled or marked, as distributing studios would only at most have their name and address written on the disc. It was generally up to the recipients to scribble on the song title or artist by hand.Audio mastering
Mastering, a form of audio post production, is the process of preparing and transferring recorded audio from a source containing the final mix to a data storage device (the master), the source from which all copies will be produced (via methods such as pressing, duplication or replication). In recent years digital masters have become usual, although analog masters, such as audio tapes, are still being used by the manufacturing industry, notably by a few engineers who have chosen to specialize in analog mastering.
Mastering requires critical listening; however, software tools exist to facilitate the process. Results still depend upon the intent of the engineer, the accuracy of the speaker monitors, and the listening environment. Mastering engineers may also need to apply corrective equalization and dynamic compression in order to optimise sound translation on all playback systems. It is standard practice to make a copy of a master recording, known as a safety copy, in case the master is lost, damaged or stolen.Buffet Crampon
Buffet Crampon is a French manufacturer of woodwind musical instruments, including oboes, flutes, saxophones, english horns and bassoons; however, the company is perhaps most famous for their clarinets, as Buffet is the brand of choice for many professionals.Buffet Crampon began manufacturing musical instruments in 1825 exclusively in France, but has since expanded their business to include production facilities in Germany and China as well. Since the company's conception, Buffet Crampon has expanded to a worldwide market. Jérôme Perrod, Buffet Group's Chief Executive Officer, runs the Buffet Crampon, Besson, B&S, Antoine Courtois, Hans Hoyer, J. Keilwerth, Meinl Weston, Powell Flutes, Scherzer, and W. Schreiber brands.Chinese lacquerware table
This carved lacquerware table in the Victoria and Albert Museum in London is from the Ming Dynasty (1368-1644). It is unique in shape and decoration and is one of the most important objects from the period. It is one of the few surviving examples in the world of a major piece of furniture produced in the 'Orchard Workshop', the Imperial lacquer workshop set up in the early Ming period and situated to the north-west of the 'Forbidden City' compound in Peking (now Beijing).By at least the Ming dynasty carved lacquer was being used all over the visible surfaces of pieces of furniture, a dauntingly expensive proposition. One of the best known pieces is this table, with three drawers, whose top has a typical imperial Ming design with a central dragon and phoenix, symbolizing the emperor and empress respectively; the pair also appear on the drawer-fronts. The table-top measures 119.5 cm by 84.5 cm and the table is 79.2 cm high. It was produced between 1425-1436 in the "Orchard Factory", and is the only piece of its size to survive from their production, the best period of Ming workmanship. As with many other pieces, the ground of the table-top relief was originally a yellow that contrasted with the red of the upper layers, but has now faded to a dark colour.The legs and edges of the top are carved with the "Flowers of the Four Seasons". The insides of the drawers are in plain red lacquer, and the outsides and undersize of the table in black lacquer. The table bears the mark of the reign of the Xuande Emperor (1426–35) and was probably made to stand in an Imperial Palace. An Imperial provenance is also suggested by the five-clawed dragons carved on the surface, each of which have been mutilated by the removal of one claw on each foot, as was often done when pieces left imperial ownership. The five-clawed dragon was only allowed to be used by the emperor, with very severe penalties for abuse, but imperial pieces were sometimes given as gifts, or pilfered by the court eunuchs to be sold at a notorious market outside the northern gate of the Forbidden City.
In the Ming period the dragon became a key imperial symbol, very often appearing on lacquer from the imperial workshops for the use of the court, or made to be given by the emperor. Initially the dragon's head was seen in the traditional profile, as here, but in the middle of the 15th century the "frontal" dragon, seen looking out full-face at the viewer, was introduced and soon became the norm in lacquer as in other media.
The table was lent to the British Museum's 2014 exhibition Ming, 50 years that changed China.Ciclopirox
Ciclopirox olamine is a synthetic antifungal agent for topical dermatologic treatment of superficial mycoses. It is most useful against Tinea versicolor. It is sold under many brand names worldwide.Conservation and restoration of lacquerware
The conservation and restoration of lacquerware prevents and mitigates deterioration or damage to objects made with lacquer. The two main types of lacquer are Asian, made with sap from the Urushi tree, and European, made with a variety of shellac and natural resins. Lacquer can be damaged by age, light, water, temperature, or damaged substrate.
Conservation treatments include dry cleaning, wet cleaning, consolidation and filling losses. Eastern cultures use Asian lacquer to repair damages and fill and consolidate losses. Western cultures typically use alternate materials that can be reversed with minimal risk to the original object.Hair spray
Hair spray (also hair lacquer or spritz) is a common cosmetic hairstyling product that is sprayed onto hair to protect against humidity and wind. Hair sprays typically consist of several components for the hair as well as a propellant.Japan black
Japan black (also called black japan) is a lacquer or varnish suitable for many substrates but known especially for its use on iron and steel. It is so named due to the history of black lacquer being associated in the West with products from Japan. Its high bitumen content provides a protective finish that is durable and dries quickly. This allowed japan black to be used extensively in the production of automobiles in the early 20th century in the United States. It can also be called japan lacquer and Brunswick black. Used as a verb, japan means "to finish in japan black." Thus japanning and japanned are terms describing the process and its products.Japan wax
Japan wax, also known as sumac wax (alternatively spelled sumach wax), vegetable wax, China green tallow, and Japan tallow, is a pale-yellow, waxy, water-insoluble solid with a gummy feel, obtained from the berries of certain sumacs native to Japan and China, such as Toxicodendron vernicifluum (lacquer tree) and Toxicodendron succedaneum (Japanese wax tree).Japan wax is a byproduct of lacquer manufacture. It is not a true wax but a fat that contains 95% palmitin. Japan wax is sold in flat squares or disks and has a rancid odor. It is extracted by expression and heat, or by the action of solvents.Japanese lacquerware
Lacquerware (漆器, shikki) is a Japanese craft with a wide range of fine and decorative arts, as lacquer has been used in urushi-e, prints, and on a wide variety of objects from Buddha statues to bento boxes for food.
A number of terms are used in Japanese to refer to lacquerware. Shikki (漆器) means "lacquer ware" in the most literal sense, while nurimono (塗物) means "coated things", and urushi-nuri (漆塗) means "lacquer coating."The history of lacquerware in Japan reaches back to the Jōmon period.
The sap of the lacquer tree, today bearing the technical description of "urushiol-based lacquer," has traditionally been used in Japan. As the substance is poisonous to the touch until it dries, the creation of lacquerware has long been practiced only by skilled dedicated artisans.Kintsugi
Kintsugi (金継ぎ, "golden joinery"), also known as Kintsukuroi (金繕い, "golden repair"), is the Japanese art of repairing broken pottery with lacquer dusted or mixed with powdered gold, silver, or platinum, a method similar to the maki-e technique. As a philosophy, it treats breakage and repair as part of the history of an object, rather than something to disguise.Lacquerware
Lacquerware are objects decoratively covered with lacquer. Lacquerware includes small or large containers, tableware, 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 the cases of China and Japan. The best known lacquer, an urushiol-based lacquer common in East Asia, is derived 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 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 a "lacquer."Nail polish
Nail polish (also known as nail varnish or nail enamel) is a lacquer that can be applied to the human fingernail or toenails to decorate and protect the nail plates. The formulation has been revised repeatedly to enhance its decorative effects, and to suppress cracking or flaking. Nail polish consists of a mix of an organic polymer and several other components, depending on the brand.Russian lacquer art
Russian lacquer art developed from the art of icon painting which came to an end with the collapse of Imperial Russia. The icon painters, who previously had been employed by supplying not only churches but people's homes, needed a way to make a living. Thus, the craft of making papier-mâché decorative boxes and panels developed, the items were lacquered and then hand painted by the artists, often with scenes from folk tales.The Book of Five Rings
The Book of Five Rings (五輪書, Go Rin no Sho) is a text on kenjutsu and the martial arts in general, written by the Japanese swordsman Miyamoto Musashi around 1645. There have been various translations made over the years, and it enjoys an audience considerably broader than only that of martial artists and people across East Asia: for instance, some foreign business leaders find its discussion of conflict and taking the advantage to be relevant to their work in a business context. The modern-day Hyōhō Niten Ichi-ryū employs it as a manual of technique and philosophy.
Musashi establishes a "no-nonsense" theme throughout the text. For instance, he repeatedly remarks that technical flourishes are excessive, and contrasts worrying about such things with the principle that all technique is simply a method of cutting down one's opponent. He also continually makes the point that the understandings expressed in the book are important for combat on any scale, whether a one-on-one duel or a massive battle. Descriptions of principles are often followed by admonitions to "investigate this thoroughly" through practice rather than trying to learn them by merely reading.
Musashi describes and advocates a two-sword fencing style (nitōjutsu): that is, wielding both katana and wakizashi, contrary to the more traditional method of wielding the katana two-handed. However, he only explicitly describes wielding two swords in a section on fighting against many adversaries. The stories of his many duels rarely refer to Musashi himself wielding two swords, although, since they are mostly oral traditions, their details may be inaccurate. Musashi states within the volume that one should train with a long sword in each hand, thereby training the body and improving one's ability to use two blades simultaneously.Toxicodendron vernicifluum
Toxicodendron vernicifluum (formerly Rhus verniciflua), also known by the common name Chinese lacquer tree, is an Asian tree species of genus Toxicodendron (formerly Rhus) native to China and the Indian subcontinent, and cultivated in regions of China, Korea and Japan. Other common names include Japanese lacquer tree, Japanese sumac, and varnish tree. The trees are cultivated and tapped for their toxic sap, which is used as a highly durable lacquer to make Chinese, Japanese, and Korean lacquerware.
The trees grow up to 20 metres tall with large leaves, each containing from 7 to 19 leaflets (most often 11–13). The sap contains the allergenic compound urushiol, which gets its name from this species' Japanese name urushi (urushi (漆)); "urushi" is also used in English as a collective term for all kinds of Asian lacquerware made from the sap of this and related Asian tree species, as opposed to European "lacquer" or Japanning made from other materials. Urushiol is the oil found in poison ivy that causes a rash.Urushiol
Urushiol is an oily mixture of organic compounds with allergenic properties found in plants of the family Anacardiaceae, especially Toxicodendron spp. (e.g., poison oak, Chinese lacquer tree, poison ivy, poison sumac) and also in parts of the mango tree.In most individuals, urushiol causes an allergic skin rash on contact, known as urushiol-induced contact dermatitis.
The name urushiol is derived from the Japanese word for the lacquer tree, Toxicodendron vernicifluum (漆, urushi). The oxidation and polymerization of urushiol in the tree's sap in the presence of moisture allows it to form a hard lacquer, which is used to produce traditional Chinese, Korean and Japanese lacquerware.Varnish
Varnish is a clear transparent hard protective finish or film. Varnish has little or no color and has no added pigment as opposed to paint or wood stain which contains pigment. However, some varnish products are marketed as a combined stain and varnish. Varnish is primarily used in wood finishing applications where the natural tones and grains in the wood are intended to be visible. It is applied over wood stains as a final step to achieve a film for gloss and protection. Varnish finishes are usually glossy but may be designed to produce satin or semi-gloss sheens by the addition of "flatting" agents.
The term "varnish" refers to the finished appearance of the product. It is not a term for any single or specific chemical composition or formula. There are many different compositions that achieve a varnish effect when applied. A distinction between spirit-drying (and generally removable) "lacquers" and chemical-cure "varnishes" (generally thermosets containing "drying" oils) is common, but varnish is a broad term historically and the distinction is not strict.Walter Laqueur
Walter Ze'ev Laqueur (26 May 1921 – 30 September 2018) was an American historian, journalist and political commentator. He was an influential scholar on the subjects of terrorism and political violence.
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