Leather 18062 225364947 2008-07-13T08:43:32Z Peachyapples21 6159721 /* Religious sensitivities to leather */ {{otheruses}} [[Image:leathertools.jpg|thumb|Modern leather-working tools]] '''Leather''' is a material created through the [[tanning]] of [[rawhide|hide]]s and [[skin]]s of [[animal]]s, primarily [[cattle]]hide. The tanning process converts the [[putrescible]] skin into a durable, long-lasting and versatile natural material for various uses. Together with [[wood]], leather formed the basis of much ancient [[technology]]. The leather industry and the [[fur]] industry are distinct industries that are differentiated by the importance of their raw materials. In the leather industry the raw materials are by-products of the [[meat]] industry, with the meat having higher value than the skin. The fur industry uses raw materials that are higher in value than the meat and hence the meat is classified as a by-product. [[Taxidermy]] also makes use of the skin of animals, but generally the head and part of the back are used. Hides and skins are also used in the manufacture of [[animal glue|glue]] and [[gelatin]]. ==Forms of leather== There are a number of processes whereby the skin of an animal can be formed into a supple, strong material commonly called leather. * '''Vegetable-tanned leather''' is tanned using [[tannin]] (hence the name "tanning") and other ingredients found in vegetable matter, tree bark, and other such sources. It is supple and brown in color, with the exact shade depending on the mix of chemicals and the color of the skin. Vegetable-tanned leather is not stable in water; it tends to discolor, and if left to soak and then dry it will shrink and become less supple and harder. In hot water, it will shrink drastically and partly gelatinize, becoming rigid and eventually brittle. [[Boiled leather]] is an example of this where the leather has been hardened by being immersed in hot water, or in boiled [[wax]] or similar substances. Historically, it was occasionally used as [[armour]] after hardening, and it has also been used for [[book binding]]. This is the only form of leather suitable for use in leather carving or stamping. * '''Chrome-tanned leather''', invented in 1858, is tanned using [[chromium sulfate]] and other salts of [[chromium]]. It is more supple and pliable than vegetable-tanned leather, and does not discolor or lose shape as drastically in water as vegetable-tanned. It is also known as wet-blue for its color derived from the chromium. More esoteric colors are possible using chrome tanning. * '''Aldehyde-tanned leather''' is tanned using [[glutaraldehyde]] or [[oxazolidine]] compounds. This is the leather that most tanners refer to as wet-white leather due to its pale cream or white color. It is the main type of leather used in chrome-free leather often seen in infant's shoes and in automobiles made with chrome-free leather. [[Formaldehyde]] tanning (being phased out due to its danger to workers and the sensitivity of many people to formaldehyde) is another method of aldehyde tanning. Brain-tanned leathers fall into this category and are exceptionally water absorbent. '''Brain tanned''' leathers are made by a labor-intensive process which uses emulsified oils, often those of animal brains. They are known for their exceptional softness and their ability to be washed. '''Chamois leather''' also falls into the category of aldehyde tanning and like brain tanning produces a highly water absorbent leather. Chamois leather is made by using oils (traditionally cod oil) that oxidise easily to produce the aldehydes that tan the leather. * '''Synthetic-tanned leather''' is tanned using aromatic [[polymer]]s such as the [[Novolac]] or [[Neradol]] types. This leather is white in color and was invented when vegetable tannins were in short supply, i.e. during the Second World War. Melamine and other amino-functional resins fall into this category as well and they provide the filling that modern leathers often require. [[Urea]]-formaldehyde resins were also used in this tanning method until dissatisfaction about the formation of free formaldehyde was realised. * '''Alum-tanned leather''' is tanned using [[aluminium]] [[salt]]s mixed with a variety of binders and [[protein]] sources, such as flour, egg yolk, etc. Purists argue that alum-tanned leather is technically "tawed" and not tanned, as the resulting material will rot in water. Very light shades of leather are possible using this process, but the resulting material is not as supple as vegetable-tanned leather. * '''Rawhide''' is made by scraping the skin thin, soaking it in lime, and then stretching it while it dries. Like alum-tanning, [[rawhide]] is not technically "leather", but is usually lumped in with the other forms. Rawhide is stiffer and more brittle than other forms of leather, and is primarily found in uses such as [[drum head]]s where it does not need to flex significantly; it is also cut up into cords for use in lacing or stitching, or for making many varieties of dog chews. Leather&mdash;usually vegetable-tanned leather&mdash;can be oiled to improve its water resistance. This supplements the natural oils remaining in the leather itself, which can be washed out through repeated exposure to water. Frequent oiling of leather, with [[mink oil]], [[neatsfoot oil]] or a similar material, keeps it supple and improves its lifespan dramatically. Leather with the hair still attached is called ''hair-on''. ===Leather types=== In general, leather is sold in three forms: * '''Full-Grain''' leather or '''Top-Grain''' is referring to the upper section of a hide that contains the epidermis or skin layer. It refers to hides that have not been sanded, buffed or snuffed(otherwise known as Corrected) in order to remove imperfections on the surface of the hide. Only the hair has been removed from the epidermis. The grain remains in its natural state which will allow the best fiber strength, resulting in greater durability. The natural grain also has natural breathability, resulting in greater comfort for clothing. The natural '''Full-Grain''' surface will wear better than other leather. Rather than wearing out, it will develop a natural "Patina" and grow more beautiful over time. The finest leather furniture and footwear are made from Full-Grain leather. For these reasons only the best raw hide are used in order to create '''Full-Grain''' or '''Top-Grain''' leather. Full grain leathers can mainly be bought as two finish types: [[aniline leather|aniline]] and [[semi-aniline]]. * '''Corrected-Grain''' leather is any '''Top-Grain''' leather that has had its surfaces sanded, buffed or snuffed in order to remove any imperfection on the surface due to insect bites, healed scars or brands. '''Top-Grain''' leather is often wrongly referred to as '''Corrected-Grain'''. Although '''Corrected-Grain''' leather is made from '''Top-Grain''' as soon as the surface is corrected in any way the leather is no longer referred to as'''Top-Grain''' leather. The hides used to create corrected leather are hides of inferior quality that do not meet the high standards for use in creating aniline or semi-aniline leather. The imperfections are corrected and an artificial grain applied. Most corrected-grain leather is used to make pigmented leather as the solid pigment helps hide the corrections or imperfections. Corrected grain leathers can mainly be bought as two finish types: [[semi-aniline]] and [[pigmented]]. * '''[[Split]]''' leather is leather that is created from the fibrous part of the hide left once the '''Top-Grain''' of the raw hide has been separated from the hide. During the splitting operation the grain and drop split are separated. The drop split can be further split (thickness allowing) into a middle split and a flesh split. In very thick hides the middle split can be separated into multiple layers until the thickness prevents further splitting. Split leather then has an artificial layer applied to the surface of the split and is embossed with a leather grain. Splits are also used to create '''Suede'''. The strongest suedes are usually made from grain splits (that have the grain completely removed) or from the flesh split that has been shaved to the correct thickness. Suede is "fuzzy" on both sides. Suede is less durable than top-grain. Suede is cheaper because many pieces of suede can be split from a single thickness of hide, whereas only one piece of top-grain can be made. However, manufacturers use a variety of techniques to make suede appear to be full-grain. For example, in one operation, glue is mixed with one side of the suede, which is then pressed through rollers; these flatten and even out one side of the material, giving it the smooth appearance of full-grain. '''Latigo''' is one of the trade names for this product. A reversed suede is a grained leather that has been designed into the leather article with the grain facing away from the visible surface. It is not a true form of suede. The International Union of Leather Technologists and Chemist Societies has a full glossary of leather terms that can be found at [http://www.iultcs.org IULTCS] Other less-common leathers include: * '''[[Buckskin (leather)|Buckskin]]''' or brained leather is a tanning process that uses animal brains or other fatty materials to alter the leather. The resulting supple, suede-like hide is usually smoked heavily to prevent it from rotting. * '''[[Patent leather]]''' is leather that has been given a high gloss finish. The original process was developed in Newark, New Jersey, by inventor Seth Boyden in 1818. Patent leather usually has a plastic coating. * '''[[Shagreen]]''' is also known as '''Stingray skin/leather'''. Applications used in furniture production date as far back as the [[art deco]] period. The word "Shagreen" originates from France and is commonly confused with a shark skin and stingray skin combination. * '''Vachetta leather''' is used in the trimmings of [[luggage]] and [[handbags]], popularized by [[Louis Vuitton]]. The leather is left untreated and is therefore susceptible to water and stains. Sunlight will cause the natural leather to darken in shade, called a [[patina]]. * '''Slink''' is leather made from the skin of unborn calves. It is particularly soft, and is valued for use in making gloves. * '''Deer skin''' is one of the toughest leathers, partially due to adaptations to their thorny and thicket filled habitats. Deerskin has been prized in many societies including indigenous Americans. Most modern deer skin is no longer procured from the wild, with "deer farms" breeding the animals specifically for the purpose of their skins. Large quantities are still tanned from wild deer hides in historic tanning towns such as [[Gloversville, New York|Gloversville]] and [[Johnstown (city), New York|Johnstown]] in upstate [[New York]]. Deer skin is used in jackets and overcoats, professional sporting equipment such as [[kendo]] [[bogu]], as well as high quality personal accessories like handbags and wallets. It commands a high price due to its relative rarity and proven durability. * '''[[Nubuck]]''' is top-grain cattle hide leather that has been sanded or buffed on the grain side, or outside, to give a slight nap of short protein fibers, producing a velvet-like surface. There are two other descriptions of leather commonly used in specialty products, such as briefcases, wallets, and luggage. * '''Belting leather''' is a full grain leather that was originally used in driving pulley belts and other machinery. It is often found on the surface of briefcases, portfolios, and wallets, and can be identified by its thick, firm feel and smooth finish. Belting leather is the only kind of leather used in luxury products that can retain its shape without the need for a separate frame; it is generally a heavy-weight of full-grain, vegetable-tanned leather. * '''[[Nappa leather]]''', or Napa leather, is chrome-tanned and is extremely soft and supple and is commonly found in higher quality wallets, toiletry kits, and other personal leather goods. The following are not 'true' leathers, but contain leather material. * '''[[Bonded Leather]]''' , or "Reconstituted Leather", is not really a true leather but a man-made material composed of 90% to 100% leather fibers (often scrap from leather tanneries or leather workshops) bonded together with latex binders to create a look and feel similar to that of genuine leather at a fraction of the cost. Bonded leather is not as durable as other leathers, and is recommended for use only if the product will be used infrequently. One example of bonded leather use is in Bible covers. * '''[[Bicast leather]]''' is a man-made product that consists of a thick layer of polyurethane applied to a substrate of low-grade or reconstituted leather. Most of the strength of bicast leather comes from the polyurethane coating. Bicast was originally made for the shoe industry and recently was adopted by the furniture industry. The original formula created by Bayer was fairly strong, but creating Bicast from the original recipe is expensive. Most of the Bicast used today is created using inferior generic chemicals resulting in an inferior material. The result is a much stiffer product that tends to delaminate, resulting in bubbles and cracking. The vast majority of leather is sold according to its area. The leather is placed through pin-wheel or electronic measuring machines and its surface area is determined. The unit of measurement is square metre, square decimetre or square foot. The thickness is also important, and this is measured using a thickness gauge (the unit of measurement is millimetres, e.g., 1.8 mm is a standard thickness for a school shoe). In some parts of the world top-grain thicknesses are described using weight units of ounces. Although the statement is in ounces only, it is an abbreviation of ounces per square foot. The thickness value can be obtained by the conversion: * 1 oz/ft² = 1/64 inch (0.4 mm) Hence, leather described as 7 to 8 oz is 7/64 to 8/64 inches (2.8 to 3.2 mm) thick. The weight is usually given as a range because the inherent variability of the material makes ensuring a precise thickness very difficult. Other leather manufacturers state the thickness directly in millimetres. ===Leather from other animals=== [[Image:Tanned leather.JPG|right|thumb|Tanned leather in [[Marrakech]]]] [[Image:Fan.jpg|right|thumb|Ostrich leather]] Today, most leather is made of [[cattle]] skin, but many exceptions exist. Lamb and deer skin are used for soft leather in more expensive apparels. Deer and elk skin are widely used in work gloves and indoor shoes. Pigskin is used in apparel and on seats of [[saddle]]s. [[Kangaroo]] skin is used to make items which need to be strong but flexible, it is the material most commonly used in high quality [[bullwhip]]s. Kangaroo leather is favored by some [[motorcycle|motorcyclists]] for use in [[Motorcycle safety clothing#Leathers|motorcycle leathers]] specifically because of its lighter weight and higher abrasion resistance compared with cowhide, thus providing greater protecting in case of a fall on the roadway. Kangaroo leather is also used for high performance soccer footwear. Leather made from more exotic skins has at different times in history been considered very beautiful. For this reason certain [[snake]]s and [[crocodile]]s have been hunted to near extinction. In the 1970s, [[ostrich]] farming for their feathers became popular, and ostrich leather became available as a side product. There are different processes to produce different finishes for many applications, i.e., upholstery, footwear, automotive products, accessories and clothing. Ostrich leather is considered one of the finest and most durable in the world and is currently used by many major fashion houses such as [[Hermès]], [[Prada]], [[Gucci]], and [[Louis Vuitton]]. Ostrich leather has a characteristic "goose bump" look because of the large follicles from which the feathers grew. In [[Thailand]], [[sting ray]] leather is used in wallets and belts in the same way as regular bovine leather. Sting ray leather is as tough and durable as hard plastic. The leather is often dyed black and covered with tiny round bumps in the natural pattern of the back ridge of an animal. These bumps are then usually dyed white to highlight the decoration. Leather clothing is also popular in Thailand. In the United States, [[bison]] leather has become popular. It is used for gloves, jackets and some baseball gloves. It is rugged but supple and has a waxy feel. Overall, leather comes from a variety of other sources, including the skins of cattle, hogs, goats, sheep, alligators, ostriches, kangaroos, and yaks. There is quite a wide range of different animal leather used both for leather garments as well as leather goods, such as handbags, wallets, purses, belts, bags and other customized leather articles. The most commonly used leather types are cow leather, sheep leather, buffalo Leather and ox leather. Of these, the most expensive is cow leather, followed by buffalo leather, ox leather and sheep leather respectively. Sheep leather is quite famous for its softness and mostly used in leather garments; however due to its smaller overall size, it cannot be used for the long coats for which cow leather and buffalo leather are widely used. ==Leather production processes== {{main|Leather Production Processes}} The leather manufacturing process is divided into three fundamental sub-processes: '''preparatory stages''', '''tanning''' and '''crusting'''. All true leathers will undergo these sub-processes. A further sub-process, surface coating can be added into the leather process sequence but not all leathers receive surface treatment. Since many types of leather exist, it is difficult to create a list of operations that all leathers must undergo. The '''preparatory stages''' are when the hide/skin is prepared for tanning. Preparatory stages may include: preservation, [[Soaking (Leather Processing)|soaking]], [[Liming (leather processing)|liming]], [[Unhairing (Leather Processing)|unhairing]], [[Fleshing (Leather Processing)|fleshing]], [[Splitting (Leather Processing)|splitting]], [[Reliming (Leather Processing)|reliming]], [[Deliming (Leather Processing)|deliming]], [[Bating (Leather Processing)|bating]], [[Degreasing( Leather Processing)|degreasing]], [[Frizing (Leather Processing)|frizing]], [[Bleaching (Leather Processing)|bleaching]], [[Pickling (Leather Processing)|pickling]] and [[Depickling (Leather Processing)|depickling]]. '''[[Tanning]]''' is the process converts the protein of the raw hide or skin into a stable material which will not putrefy and is suitable for a wide variety of end applications. The principal difference between raw hides and tanned hides is that raw hides dry out to form a hard inflexible material that when re-wetted (or wetted back) putrefy, whilst tanned material dries out to a flexible form that does not become putrid when wetted back. There is a large number of different tanning methods and materials that can be used, the choice is ultimately dependent on the end application of the leather. The most commonly used tanning material is chromium, which leaves the leather once tanned a pale blue colour (due to the chromium), this product is commonly called “wet blue”. The hides once they have finished pickling will typically be between [[pH]] of 2.8-3.2. At this point the hides would be loaded in a drum and immersed in a float containing the tanning liquor. The hides are allowed to soak (while the drum slowly rotates about its axle) and the tanning liquor slowly penetrates through the full substance of the hide. Regular checks will be made to see the penetration by cutting the cross section of a hide and observing the degree of penetration. Once a good even degree of penetration exists, the pH of the float is slowly raised in a process called basification. This basification process fixes the tanning material to the leather and the more tanning material fixed the higher the hydrothermal stability and increased shrinkage temperature resistance of the leather. The pH of the leather when chrome tanned would typically finish somewhere between 3.8-4.2. '''Crusting''' is when the hide/skin is thinned, retanned and lubricated. Often a coloring operation is included in the crusting sub-process. The chemicals added during crusting have to be fixed in place. The culmination of the crusting sub-process is the drying and softening operations. Crusting may include the following operations: [[Wetting Back (Leather Processing)|wetting back]], [[Sammying (Leather Processing)|sammying]], [[Splitting (Leather Processing)|splitting]], [[Shaving (Leather Processing)|shaving]], [[Rechroming (Leather Processing)|rechroming]] [[Neutralisation (Leather Processing)|neutralisation]], [[Retanning (Leather Processing)|retanning]], [[Dyeing (Leather Processing)|dyeing]], [[Fatliquoring (Leather Processing)|fatliquoring]], [[Filling (Leather Processing)|filling]], [[Stuffing (Leather Processing)|stuffing]], [[Stripping (Leather Processing)|stripping]], [[Whitening (Leather Processing)|whitening]], [[Fixation (Leather Processing)|fixation]], [[Setting (Leather Processing)|setting]], [[Drying (Leather Processing)|drying]], [[Conditioning (Leather Processing)|conditioning]], [[Milling (Leather Processing)|milling]], [[Staking (Leather Processing)|staking]] and [[Buffing (Leather Processing)|buffing]]. For some leathers a surface coating is applied. Tanners refer to this as finishing. Finishing operations may include: [[Oiling (Leather Processing)|oiling]], [[Brushing (Leather Processing)|brushing]], [[Padding (Leather Processing)|padding]], [[Impregnation (Leather Processing)|impregnation]], [[Buffing (Leather Processing)|buffing]], [[Spraying (Leather Processing)|spraying]], [[Roller Coating (Leather Processing)|roller coating]], [[Curtain Coating (Leather Processing)|curtain coating]], [[Polishing (Leather Processing)|polishing]], [[Plating (Leather Processing)|plating]], [[Embossing (Leather Processing)|embossing]], [[Ironing (Leather Processing)|ironing]], [[Ironing/Combing (Leather Processing)|ironing/combing]](for hair-on)and [[Glazing (Leather Processing)|glazing]]. ==Role of enzymes in leather production== Enzymes like proteases, lipases and amylases have an important role in the soaking, dehairing, degreasing, and bating operations of leather manufacturing. Proteases are the most commonly used enzymes in leather production. The enzyme used should not damage or dissolve collagen or keratin, but should be able to hydrolyse casein, elastin, albumin and globulin-like proteins, as well as non-structured proteins which are not essential for leather making. It is especially important to hydrolyse the elastin if the leather is to be limed, or treated with [[calcium hydroxide]]; if not treated properly before liming, the elastin will harden and the grain will be loose. This process is called bating<ref>{{citation | title = Fundamentals of Leather Manufacture | first = E. | last = Heidemann | page = 211 | publisher = Eduard Roether KG | isbn = 3792902060}}</ref>. Lipases are used in the degreasing operation to hydrolyse fat particles embedded in the skin<ref>{{citation | title = Physical Chemistry of Leather Making | first = K. | last = Bienkiewicz | page = 226 | publisher = Robert E. Krieger | isbn = 0898743044}}</ref>.. Amylases are used to soften skin, to bring out the grain, and to impart strength and flexibility to the skin. These enzymes are rarely (if ever) used. ==Preservation and conditioning of leather== The natural fibers of leather will break down with the passage of time. Acidic leathers are particularly vulnerable to '''[[red rot]]''', which causes powdering of the surface and a change in consistency. Damage from red rot is aggravated by high temperatures and relative humidities, and is irreversible. Exposure to long periods of low relative humidities (below 40%) can cause leather to become desiccated, irreversibly changing the fibrous structure of the leather. Various treatments are available such as [[conditioner]]s, but these are not recommended by [[art conservation|conservators]] since they impregnate the structure of the leather artifact with active chemicals, are sticky, and attract stains. ===Leather in book binding=== Leather used in book binding has many of the same preservation needs: protection from high temperatures, high relative humidity, low relative humidity, fluctuations in relative humidity, light exposure, dust buildup, pollution, mold, and bug infestation.<ref name=mumford>Mumford, John.[http://www.bl.uk/services/npo/pdf/bookbindings.pdf “Understanding and Caring for Bookbindings”],[[NPO Preservation Guidance Occasional Papers]],[[2006-11]]. Retrieved on [[2008-04-05]].</ref><ref name=fahey>Fahey, Mary.[http://www.hfmgv.org/explore/artifacts/archival.asp “The Care and Preservation of Archival Materials”],”[[The Henry Ford]]”. Retrieved on [[2008-04-06]].</ref> For books with red rot, acid-free phase boxes and/or polyester dust jackets (Dupont Mylar Type D® or ICI Mellinex 516®) are recommended to protect the leather from further handling damage and as well as to prevent the residues from getting on hands, clothes, the text block, and nearby books.<ref name=loc>Library of Congress.[http://www.loc.gov/preserv/care/leather.html “Leather Dressing”]. Retrieved on [[2008-04-05]].</ref> The debate on the use of dressings for preservation of book bindings has spanned several decades as research and experimental evidence have slowly accumulated. The main argument is that, done incorrectly, there are multiple disadvantages and that, done correctly, there is little to no preservation advantage. Pamphlets and guidelines give numerous downsides to dressings use, including: the dressing becoming increasingly acidic, discolor and stain the leather, oxidize (penetration and expansion of oils including displacement and weakening of fibers) and stiffen, leave a sticky surface, collect dust, wick into adjacent materials, form unstable surface spews, encourage biological deterioration and mold growth, block surface porosity, impede further treatment, wet and swell the leather, affect surface finishes, and desiccate or dry out the leather.<ref name=society>Society of Rocky Mountain Archivists.[http://www.srmarchivists.org/preservation/publications/leather.htm “Leather Dressing: ‘To Dress or not to Dress’”],”[[National Park Service Conserve O Gram]]”, Vol. 9, No.1, [[2004-12]]. Retrieved [[2008-04-05]].</ref>Meanwhile, scientific experiments have shown no great benefits.<ref name=mccrady>McCrady, Ellen.[http://palimpsest.stanford.edu/byorg/abbey/an/an05/an05-2/an05-206.html “Research on the Dressing and Preservation of Leather”],“[[Abbey Newsletter]]”, V.5 No.2, [[1981-04]]. Retrieved [[2008-04-05]].</ref>The main authorities on the subject therefore discourage it, with a caveat for special cases done under the direction of a conservator.<ref name=loc/><ref name=society/><ref name=mumford/> ==Working with leather== {{main|Leather crafting}} Leather can be decorated by a variety of methods, including [[pyrography]] and [[beading]]. ==Cordwain== <!--Too short for separate article – links to 'Leather#Cordwain' exist --> Cordwain, once a synonym to [[shell cordovan|Cordovan]] (through [[Old French]] cordewan) meaning "from [[Córdoba, Spain|Córdoba]]". Painted or [[Gilding|gilded]] [[embossed]] leather decoration for walls, a 12th century north African style, was introduced to [[Spain]] (hence it is sometimes referred to as 'Spanish leather'). Around the turn of the 15th-16th century the technique reached [[County of Flanders|Flanders]] and [[Duchy of Brabant|Brabant]] in the [[Low Countries]]. Though there were [[Artisan|craftsmen]] in several cities (such as [[Antwerp]], [[Brussels]], [[Ghent]]), the major [[handicraft]] center for this '''cordwain''' was [[Mechelen]], where it was mentioned as early as 1504. Since the second half of the 18th century, this luxurious [[artisan]] product is no longer made.<ref>[http://profkoslow.com/publications/AtlasofWorldArt.html Article by Susan Koslow, contributor to the Atlas of World Art]</ref> Cordwainer is still used to describe someone in the profession of [[shoemaking]]. ==Leather in modern culture== Leather, due to its excellent abrasion and wind resistance, found a use in rugged occupations. The enduring image of a [[cowboy]] in leather chaps gave way to the leather-jacketed and leather-helmeted aviator. When motorcycles were invented, some riders took to wearing heavy leather jackets to protect from [[road rash]] and wind blast; some also wear chaps or full leather pants to protect the lower body. Many sports still use leather to help in playing the game or protecting players: due to its flexible nature it can be formed and flexed for the occasion. As leather can also be a [[metonym]]ical term for objects made from it, the term '''leathering''' is as logical as ''tanning'' in the sense of a [[physical punishment]] (such as a severe [[spanking]]) applied with a leather [[whip]], [[martinet]] etcetera. [[Leather fetishism]] is the name popularly used to describe a [[sexual fetishism|fetishistic]] attraction to people wearing leather, or in certain cases, to the garments themselves. The word leather itself became synonymous with [[sado-masochism]] in the 1980s after achieving that status in [[gay slang|homosexual jargon]] in the 1970s. A number of [[rock group]]s, particularly [[Heavy Metal music|heavy metal]] groups such as [[Judas Priest]] and [[Scorpions (band)|Scorpions]], are well-known for wearing leather clothing. Leather clothing, particularly jackets, almost come as standard in the heavy metal subculture. [[Extreme metal]] bands, especially [[black metal]] bands, have extensive leather clothing, i.e. leather trousers, accessories etc. In today's times, many cars and trucks come optional or standard with 'leather' seating. This can range from cheap vinyl material, found on some low cost vehicles, to Nappa leather, found on luxury car brands like [[Mercedes-Benz]] and [[Audi]]. Leather [[biodegrade]]s slowly, e.g. a pair of [[leather shoes]] takes 25-40 years to decompose. == Religious sensitivities to leather == In countries with harmonious multi-religious environments, leather vendors are typically careful to clarify the kinds of leather used in their products. For example, leather shoes will bear a label identifying the animal from which the leather was taken. In this way, a follower of [[Islam]] would not accidentally purchase [[pigskin]] leather, and a [[Hindu]] would avoid [[cow]] leather. Such taboos increase the demand for religiously neutral leathers like ostrich and deer. Judaism forbids wearing leather shoes on Yom Kippur, Tisha B'Av, and during mourning. In Muslim countries, products made of leather were normally banned as due to the religious concerns imposed by some Islamic scholars, but in the mid-20th century, some eminent scholars {{who?}}from the Muslim world have made significant efforts to foster awareness about the origin of leather. ==Concern for animals and alternatives== Some [[vegan]] and [[Animal Rights|animal rights activists]] have boycotted use of all leather items, believing the practice of wearing animal hides is unnecessary and vulgar in today's society. Animal rights groups such as [[PETA]] have issued fact sheets calling for boycotts and encouraging use of alternative materials such as [[Artificial leather|synthetic leathers]] produced from petro-chemicals. Many pseudo-leather materials have been developed, allowing those who wish to wear leather-like garments to do so without actually wearing leather. One example of this is [[vegan microfiber]], which claims to be stronger than leather when manufactured with strength in mind. Vinyl materials, [[Pleather]], [[Durabuck]], [[NuSuede]], [[Hydrolite]], and other alternatives exist, providing some features similar to leather. Drawbacks include the fact that the product is inorganic and not [[biodegradable]] along with concerns related to pollution in the production process. ==See also== '''Types of leather''' * [[Aniline leather]],a leather treated with aniline as a dye * [[Artificial leather]], a fabric of finish intended to substitute for leather * [[Bicast leather]], a synthetic upholstery product * [[Boiled leather]], a historical construction material * [[Bonded Leather]], man-made material composed of leather fibers * [[Chamois leather]], leather made from the skin of the mountain antelope or Chamois * [[Corinthian leather]], a marketing term used by Chrysler in the 1970s * [[Morocco leather]], a type of sheepskin dyed red * [[Nappa leather]], a full-grain leather * [[Ostrich leather]], leather from an ostrich * [[Patent leather]], leather with a high gloss and shiny finish * [[Pleather]], a term for artificial leather * [[Poromeric imitation leather]], a group of synthetic leather substitutes * [[Vegan leather]], an artificial alternative to traditional leather '''Leather fabrication''' * [[Leather carving]], a process of cutting and stamping to give a three-dimensional appearance * [[Leather crafting]], the practice of making leather into crafts or pieces of art * [[Liming (leather processing)]], a process of treating leather * [[British Museum leather dressing]], a conservator's treatment for display items * [[Tanning]] '''Other''' * [[Mink oil]], leather treatment * [[Neatsfoot oil]], leather treatment * [[Saddle soap]], leather cleaning and conditioning * [[Leather subculture]] * [[Adarga]], a hard leather shield * [[Horse tack]], various equipment and accessories worn by horses, much of which is made of leather * [[Henry Burk|Henry Burk - inventor of the alum and sumac tanning process]] * [[Leather skirt]] ==External links== {{commonscat|Leather}} * [http://www.furnitureclinic.co.uk/All_About_Leather.htm All About Leather] * [http://www.sealeatherwear.com/fish-leather-tanning.php Fish Leather Tanning] ==References== {{reflist}} [[Category:Leather| ]] [[gn:Vakapi]] [[bn:পাকাচামড়া]] [[bs:Koža (materijal)]] [[br:Lêr]] [[ca:Cuir]] [[cs:Kůže (materiál)]] [[da:Læder]] [[de:Leder]] [[es:Cuero]] [[eo:Ledo]] [[fr:Cuir]] [[gl:Coiro]] [[ko:가죽]] [[it:Cuoio]] [[he:עור (חומר גלם)]] [[nl:Leer (stof)]] [[cr:ᐲᔖᑲᓐ]] [[ja:皮革]] [[no:Lær]] [[nn:Lêr]] [[pl:Skóra (surowiec)]] [[pt:Couro]] [[ru:Кожевенное производство]] [[scn:Coriu]] [[simple:Leather]] [[sl:Usnje]] [[fi:Nahka]] [[sv:Läder]] [[ta:தோல்சரக்கு நுட்பியல்]] [[chr:ᎦᏃᏥ]] [[tr:Cilt (Organ)]] [[tl:Katad]] [[zh:皮革]]