Tanned leather in Marrakech

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Tanning is the process of converting putrescible skin into non-putrescible leather, usually with tannin, an acidic chemical compound that prevents decomposition and often imparts color. Tanning leather involves a process which permanently alters the protein structure of skin so that it can not ever return to rawhide. Making rawhide does not require the use of tannin and is made simply by removing the flesh and then the hair by way of soaking in an aqueous solution (often called liming-lime and water or bucking-wood ash and water=lye), then scraping over a beam with a somewhat dull knife, and then leaving to dry, usually stretched on a frame so that it dries flat. The two aforementioned solutions for removing the hair also act to clean the fiber network of the skin and therefore allow penetration and action of the tanning agent. A suntanned arm showing browner skin where it has been exposed. ... Image File history File linksMetadata Download high resolution version (1600x1200, 671 KB) Summary Freshly tanned leather in Marrakech Licensing File links The following pages link to this file: Leather Tanning Metadata This file contains additional information, probably added from the digital camera or scanner used to create or digitize it. ... Image File history File linksMetadata Download high resolution version (1600x1200, 671 KB) Summary Freshly tanned leather in Marrakech Licensing File links The following pages link to this file: Leather Tanning Metadata This file contains additional information, probably added from the digital camera or scanner used to create or digitize it. ... For the record label, see Marrakesh Records. ... Image File history File links Question_book-3. ... Putrefaction is the decomposition of animal proteins, especially by anaerobic microorganisms. ... For people named Leather, see Leather (surname). ... A bottle of tannic acid. ... For other uses, see Acid (disambiguation). ... Look up chemical compound in Wiktionary, the free dictionary. ... For other uses, see Decomposition (disambiguation). ...

Ancient methods of tanning

Tanneries at Fez

In ancient history, tanning was considered a noxious or "odiferous trade" and relegated to the outskirts of town, amongst the poor. Indeed, tanning by ancient methods is so foul smelling that tanneries are still isolated from those towns today where the old methods are used. The ancients used leather for waterskins, bags, harnesses, boats, armor, quivers, scabbards, boots and sandals. Around 2500 BC, the Sumerians began using leather, affixed by copper studs, on chariot wheels. Image File history File links Download high resolution version (1200x900, 510 KB) Fez, Morocco 2004 september camer=KODAK 7440 Source: Csörföly Dániel File links The following pages link to this file: Fes, Morocco ... Image File history File links Download high resolution version (1200x900, 510 KB) Fez, Morocco 2004 september camer=KODAK 7440 Source: Csörföly Dániel File links The following pages link to this file: Fes, Morocco ... “Ancient” redirects here. ... A city-state is a region controlled exclusively by a city. ... A boy from an East Cipinang trash dump slum in Jakarta, Indonesia shows what he found. ... Paper bag redirects here. ... The term harness has been used for many centuries for part of the collection of equipment known as horse tack, essential in the domestic, military, and agrarian use of horses. ... For other uses, see Boat (disambiguation). ... Armor or armour (see spelling differences) is protective clothing intended to defend its wearer from intentional harm in combat and military engagements, typically associated with soldiers. ... For other uses, see Quiver (disambiguation). ... A scabbard is a sheath for holding a sword or other large blade. ... For other senses of this word, see boot (disambiguation). ... Modern multi-colored Sandalette Yoga sandals In some parts of the United States, this type of sandal is referred to in slang as the mandal in that it is worn primarily by men. ... (Redirected from 2500 BC) (26th century BC - 25th century BC - 24th century BC - other centuries) (4th millennium BC - 3rd millennium BC - 2nd millennium BC) Events 2900 - 2334 BC -- Mesopotamian wars of the Early Dynastic period 2494 BC -- End of Fourth Dynasty, start of Fifth Dynasty in Egypt. ... Sumer (or Šumer; Sumerian: KI-EN-GIR [1]) was the earliest known civilization of the ancient Near East, located in lower Mesopotamia (modern Iraq), from the time of the earliest records in the mid 4th millennium BC until the rise of Babylonia in the late 3rd millennium BC. The term... For other uses, see Copper (disambiguation). ... Look up Stud in Wiktionary, the free dictionary. ... For other uses, see Chariot (disambiguation). ... For other uses, see Wheel (disambiguation). ...

Skins typically arrived at the tannery dried stiff and dirty with soil and gore. First, the ancient tanners would soak the skins in water to clean and soften them. Then they would pound and scour the skin to remove any remaining flesh and fat. Next, the tanner needed to remove the hair fibers from the skin. This was done by either soaking the skin in urine, painting it with an alkaline lime mixture, or simply letting the skin putrefy for several months then dipping it in a salt solution. After the hair fibers were loosened, the tanners scraped them off with a knife. Flesh by definition is composite of all the soft parts of the body of a human or animal which is between the skin and the bones. ... For other uses, see FAT. Fats consist of a wide group of compounds that are generally soluble in organic solvents and largely insoluble in water. ... For the 1968 stage production, see Hair (musical), for the 1979 film, see Hair (film). ... Fiber or fibre[1] is a class o f materials that are continuous filaments or are in discrete elongated pieces, similar to lengths of thread. ... This article is about the urine of animals generally. ... This article is about common table salt. ... Making a saline water solution by dissolving table salt (NaCl) in water This article is about chemical solutions. ... This article is about the tool. ...

Once the hair was removed, the tanners would bate the material by pounding dung into the skin or soaking the skin in a solution of animal brains. Among the kinds of dung commonly used were that of dogs or pigeons. Sometimes the dung was mixed with water in a large vat, and the prepared skins were kneaded in the dung water until they became supple, but not too soft. The ancient tanner might use his bare feet to knead the skins in the dung water, and the kneading could last two or three hours. Horse feces Feces, faeces, or fæces (see spelling differences) is a waste product from an animals digestive tract expelled through the anus (or cloaca) during defecation. ...

It was this combination of animal feces mixed with decaying flesh that made ancient tanneries so odiferous.

Children employed as dung gatherers were a common sight in ancient cities. Also common were "piss-pots" located on street corners, where human urine could be collected for use in tanneries or by washerwomen. In some variations of the process, cedar oil, alum or tannin were applied to the skin as a tanning agent. As the skin was stretched, it would lose moisture and absorb the agent. Cedar oil was used as the base for paints by the ancient Sumerians. ... A crystal of alum Alum, (IPA: ) (aluminium potassium sulfate,) in chemistry, is a term given to the crystallized double sulfates of the typical formula M+2SO4·M3+2(SO4)3·12H2O, where M+ is the sign of an alkali metal (or generally monovalent cation) (lithium, sodium, potassium, rubidium, or caesium... Dew on a spider web Moldy bread Moisture generally refers to the presence of water, often in trace amounts. ...

Leftover leather would be turned into glue. Tanners would place scraps of hides in a vat of water and let them deteriorate for months. The mixture would then be placed over a fire to boil off the water to produce hide glue. An animal glue is an adhesive that is created by prolonged boiling of animal connective tissue. ... Look up hide in Wiktionary, the free dictionary. ... Impact from a water drop causes an upward rebound jet surrounded by circular capillary waves. ... For other uses, see Fire (disambiguation). ... Boiling, a type of phase transition, is the rapid vaporization of a liquid, which typically occurs when a liquid is heated to its boiling point, the temperature at which the vapor pressure of the liquid is equal to the pressure exerted on the liquid by the surrounding atmospheric pressure. ... An animal glue is an adhesive that is created by prolonged boiling of animal connective tissue. ...

Variations of these methods are still used by do-it-yourself outdoorsmen to tan hides. The use of brains and the idea that each animal (except buffalo) has just enough brains for the tanning process have led to the saying "Every animal has just enough brains to preserve its own hide, dead or alive."

Modern methods of tanning

Tanneries of Marrakech

Two men pressing the leather near the end of the tanning process in an American tannery. circa: 1976

The first stage is the preparation for tanning. The second stage is the actual tanning and other chemical treatment. The third stage applies finishing to the surface. Image File history File links Size of this preview: 800 × 600 pixelsFull resolution‎ (1,304 × 978 pixels, file size: 2. ... Image File history File links Size of this preview: 800 × 600 pixelsFull resolution‎ (1,304 × 978 pixels, file size: 2. ... For the record label, see Marrakesh Records. ... Image File history File linksMetadata No higher resolution available. ... Image File history File linksMetadata No higher resolution available. ... Finishing is the procedure that some single malt Scotch whisky undergoes whereby the spirit is matured in a cask of a particular origin and then spends time in a cask of different origin. ...

Preparing hides begins by curing them with salt. In wet-salting, the hides are heavily salted, then pressed into packs for about 30 days. In brine-curing the hides are agitated in a salt water bath for about 16 hours. The hides are then soaked in clean water to remove the salt and a lime/water solution to loosen the hair. The majority of hair is then removed using a machine with remaining hair being removed by hand using a dull knife, a process known as scudding. Depending on the end use of the leather, hides may be treated with enzymes to soften them. In polymer chemistry and Process Engineering, curing refers to the toughening or hardening of a polymer material by cross-linking of polymer chains, brought about by chemical additives, ultraviolet radiation or heat. ... For the sports equipment manufacturer, see Brine, Corp. ... Neuraminidase ribbon diagram An enzyme (in Greek en = in and zyme = blend) is a protein, or protein complex, that catalyzes a chemical reaction and also controls the 3D orientation of the catalyzed substrates. ...

Tanning can be performed with either vegetable or mineral methods. Before tanning, the skins are unhaired, degreased, desalted and soaked in water over a period of 6 hours to 2 days. To prevent damage of the skin by bacterial growth during the soaking period, biocides, such as pentachlorophenol, are used. A biocide is a chemical substance capable of killing different forms of living organisms used in fields such as medicine, agriculture, forestry, and mosquito control. ... Pentachlorophenol (C6HCl5O) is a synthetic fungicide which is an organochloride. ...

Vegetable tanning uses tannin (this is where the name tanning comes from). Tannin occurs naturally in bark. The primary barks used in modern times are chestnut, oak, tanoak, hemlock, quebracho, mangrove, wattle and myrobalan. Hides are stretched on frames and immersed for several weeks in vats of increasing concentrations of tannin. Vegetable tanned hide is flexible and is used for luggage and furniture. Species Castanea alnifolia - Bush Chinkapin* Castanea crenata - Japanese Chestnut Castanea dentata - American Chestnut Castanea henryi - Henrys Chestnut Castanea mollissima - Chinese Chestnut Castanea ozarkensis - Ozark Chinkapin Castanea pumila - Allegheny Chinkapin Castanea sativa - Sweet Chestnut Castanea seguinii - Seguins Chestnut * treated as a synonym of by many authors Chestnut is a... Species See List of Quercus species The term oak can be used as part of the common name of any of several hundred species of trees and shrubs in the genus Quercus (from Latin oak tree), and some related genera, notably Cyclobalanopsis and Lithocarpus. ... Binomial name Lithocarpus densiflorus (Hook. ... Species Eastern Hemlock Carolina Hemlock Taiwan Hemlock Northern Japanese Hemlock Himalayan Hemlock Forrests Hemlock Western Hemlock Mountain Hemlock Southern Japanese Hemlock Tsuga is a genus of conifers in the family Pinaceae. ... Quebracho is one of the common names, in Spanish, of at least three similar species of trees that grow in the Gran Chaco region of South America: Schinopsis lorentzii (quebracho colorado santiagueño), of the family Anacardiaceae; Schinopsis balansae (quebracho colorado chaqueño), of the same family; Aspidosperma quebracho-blanco... Above and below water view at the edge of the mangal. ... For other uses, see Acacia (disambiguation). ... The common name myrobalan refers to several unrelated plant species: Prunus cerasifera (cherry plum) Several species of the genus Terminalia See also: Mirabelle This is a disambiguation page—a list of articles associated with the same title. ...

Mineral tanning usually uses chromium. In the raw state chrome tanned skins are blue and therefore referred to as "wet blue". Chrome tanning is faster than vegetable tanning (less than a day for this part of the process) and produces a stretchable leather which is excellent for use in handbags and garments. (Encarta, 2003) REDIRECT [[ Insert text]]EWWWWWWWWWWWWW YO General Name, symbol, number chromium, Cr, 24 Chemical series transition metals Group, period, block 6, 4, d Appearance silvery metallic Standard atomic weight 51. ...

Depending on the finish desired, the hide may be waxed, rolled, lubricated, injected with oil, split, shaved and, of course, dyed. Suedes, nubucks, etc. are finished by raising the nap of the leather by rolling with a rough surface. This article does not cite any references or sources. ... There are very few or no other articles that link to this one. ...

Another use

The term tanning is also used metaphorically for a hiding in the sense of physical punishment (such as a severe spanking) which leaves clear marks (reddening, stripes or even scars) on the beaten skin. It has been suggested that this article or section be merged into Corporal punishment. ...

References

• Microsoft Encarta, 2003

External links

• Chrome Tanning Process for Cowhide Rugs - See FAQs

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