Leather

Leather is a natural durable and flexible material created by tanning animal rawhides and skins. The most common raw material is cattle hide. It can be produced at manufacturing scales ranging from artisan to modern industrial scale.

Leather is used to make a variety of articles, including footwear, automobile seats, clothing, bags, book bindings, fashion accessories, and furniture. It is produced in a wide variety of types and styles and decorated by a wide range of techniques. The earliest record of leather artifacts dates back to 2200 BC.

Leathertools
A variety of leather products and leather-working tools

Production processes

Ledertrocknung in Suai
Drying of leather in East Timor
Leather tanning, Fes
Leather tanning in Fes, Morocco
Tanned leather
Tanned leather in Marrakech

The leather manufacturing process is divided into three fundamental subprocesses: preparatory stages, tanning, and crusting. A further subprocess, finishing, can be added into the leather process sequence, but not all leathers receive finishing.

The preparatory stages are when the hide is prepared for tanning. Preparatory stages may include: soaking, unhairing, liming, deliming, bating, bleaching, and pickling.

Tanning is a process that stabilizes the proteins, particularly collagen, of the raw hide to increase the thermal, chemical and microbiological stability of the hides and skins, making it suitable for a wide variety of end applications. The principal difference between raw and tanned hides is that raw hides dry out to form a hard, inflexible material that, when rewetted, will putrefy, while tanned material dries to a flexible form that does not become putrid when rewetted.

Many tanning methods and materials exist. The typical process sees tanners load the hides into a drum and immerse them in a tank that contains the tanning "liquor". The hides soak while the drum slowly rotates about its axis, and the tanning liquor slowly penetrates through the full thickness of the hide. Once the process achieves even penetration, workers slowly raise the liquor's pH in a process called basification, which fixes the tanning material to the leather. The more tanning material fixed, the higher the leather's hydrothermal stability and shrinkage temperature resistance.

Crusting is a process that thins and lubricates leather. It often includes a coloring operation. Chemicals added during crusting must be fixed in place. Crusting culminates with a drying and softening operation, and may include splitting, shaving, dyeing, whitening or other methods.

For some leathers, tanners apply a surface coating, called "finishing". Finishing operations can include oiling, brushing, buffing, coating, polishing, embossing, glazing, or tumbling, among others.

Leather can be oiled to improve its water resistance. This currying process after tanning 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.[1]

Tanning methods

Tanning processes largely differ in which chemicals are used in the tanning liquor. Some common types include:

  • Vegetable-tanned leather is tanned using tannins extracted from vegetable matter, such as tree bark prepared in bark mills. It is the oldest known method. It is supple and brown in color, with the exact shade depending on the mix of materials and the color of the skin. The color tan derives its name from the appearance of undyed vegetable-tanned leather. Vegetable-tanned leather is not stable in water; it tends to discolor, and if left to soak and then dry, it shrinks and becomes harder. This is a feature of oak-bark-tanned leather that is exploited in traditional shoemaking. In hot water, it shrinks drastically and partly congeals, 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 armor after hardening, and it has also been used for book binding.
  • Chrome-tanned leather, invented in 1858, is tanned using chromium sulfate and other chromium salts . It is also known as "wet blue" for the pale blue color of the undyed leather. The chrome tanning method usually takes approximately one day to complete, making it best suited for large-scale industrial use. This is the most common method in modern use. It is more supple and pliable than vegetable-tanned leather and does not discolor or lose shape as drastically in water as vegetable-tanned. However, there are environmental concerns with this tanning method, as chromium is a heavy metal.
  • Aldehyde-tanned leather is tanned using glutaraldehyde or oxazolidine compounds. It is referred to as "wet white" due to its pale cream color. It is the main type of "chrome-free" leather, often seen in shoes for infants and automobiles. Formaldehyde has been used for tanning in the past; it is being phased out due to danger to workers and sensitivity of many people to formaldehyde.
    • Chamois leather is a form of aldehyde tanning that produces a porous and highly water-absorbent leather. Chamois leather is made using marine oils (traditionally cod oil) that oxidize to produce the aldehydes that tan the leather.
  • Brain tanned leathers are made by a labor-intensive process that uses emulsified oils, often those of animal brains such as deer, cattle, and buffalo. They are known for their exceptional softness and washability.
  • Alum leather is transformed using aluminium salts mixed with a variety of binders and protein sources, such as flour and egg yolk. Alum leather is not actually tanned; rather the process is called "tawing", and the resulting material reverts to rawhide if soaked in water long enough to remove the alum salts.

Grades

In general, leather is produced in the following grades:

  • Top-grain leather includes the outer layer of the hide, known as the grain, which features finer, more densely packed fibers, resulting in strength and durability. Depending on thickness, it may also contain some of the more fibrous under layer, known as the corium. Types of top-grain leather include:
    • Full-grain leather contains the entire grain layer, without any removal of the surface. Rather than wearing out, it develops a patina during its useful lifetime. It is usually considered the highest quality leather. Furniture and footwear are often made from full-grain leather. Full-grain leather is typically finished with a soluble aniline dye. Russia leather is a form of full-grain leather.
    • Corrected grain leather has the surface subjected to finishing treatments to create a more uniform appearance. This usually involves buffing or sanding away flaws in the grain, then dyeing and embossing the surface.
    • Nubuck is top-grain leather that has been sanded or buffed on the grain side to give a slight nap of short protein fibers, producing a velvet-like surface.
  • Split leather is created from the corium left once the top-grain has been separated from the hide, known as the drop split. In thicker hides, the drop split can be further split into a middle split and a flesh split.
    • Suede is made from the underside of a split to create a soft, napped finish. It is often made from younger or smaller animals, as the skins of adults often result in a coarse, shaggy nap.
    • Bicast leather is split leather that has a polyurethane or vinyl layer applied to the surface and embossed to give it the appearance of a grain. It is slightly stiffer than top-grain leather but has a more consistent texture.
    • Patent leather is leather that has been given a high-gloss finish by the addition of a coating. Dating to the late 1700s, it became widely popular after inventor Seth Boyden developed the first mass-production process, using a linseed oil-based lacquer, in Newark, New Jersey, in 1818. Modern versions are usually a form of bicast leather.
  • Bonded leather, also called reconstituted leather, is a material that uses leather scraps that are shredded and bonded together with polyurethane or latex onto a fiber mesh. The amount of leather fibers in the mix varies from 10% to 90%, affecting the properties of the product.[2]

From other animals

«PhoneCases»
Phone cases in ostrich leather

Today, most leather is made of cattle hides, which constitute about 65% of all leather produced. Other animals that are used include sheep, about 13%, goats, about 11%, and pigs, about 10%. Obtaining accurate figures from around the world is difficult, especially for areas where the skin may be eaten.[3][4] Other animals mentioned below only constitute a fraction of a percent of total leather production.

Horse hides are used to make particularly durable leathers. Shell cordovan is a horse leather made not from the outer skin but an under layer found only in equine species called the shell. It is prized for its mirror-like finish and anti-creasing properties.

Lamb and deerskin are used for soft leather in more expensive apparel. Deerskin is widely used in work gloves and indoor shoes.

Reptilian skins, such as alligator, crocodile, and snake, are noted for their distinct patterns that reflect the scales of their species. This has led to hunting and farming of these species in part for their skins.

Kangaroo leather is used to make items that must be strong and flexible. It is the material most commonly used in bullwhips. Some motorcyclists favor kangaroo leather for motorcycle leathers because of its light weight and abrasion resistance.[5] Kangaroo leather is also used for falconry jesses, soccer footwear,[6] and boxing speed bags.[7]

Although originally raised for their feathers in the 19th century, ostriches are now more popular for both meat and leather.[8] Ostrich leather has a characteristic "goose bump" look because of the large follicles where the feathers grew. Different processes produce different finishes for many applications, including upholstery, footwear, automotive products, accessories, and clothing.

In Thailand, stingray leather is used in wallets and belts. Stingray leather is tough and durable. 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. Stingray rawhide is also used as grips on Chinese swords, Scottish basket hilted swords, and Japanese katanas. Stingray leather is also used for high abrasion areas in motorcycle racing leathers (especially in gloves, where its high abrasion resistance helps prevent wear through in the event of an accident.)

Environmental impact

Leather produces some environmental impact, most notably due to:

Carbon footprint

One estimate of the carbon footprint of leather goods is 0.51 kg of CO2 equivalent per £1 of output at 2010 retail prices, or 0.71 kg CO2eq per £1 of output at 2010 industry prices.[9]

Water footprint

One ton of hide or skin generally produces 20 to 80 m3 of waste water, including chromium levels of 100–400 mg/l, sulfide levels of 200–800 mg/l, high levels of fat and other solid wastes, and notable pathogen contamination. Producers often add pesticides to protect hides during transport. With solid wastes representing up to 70% of the wet weight of the original hides, the tanning process represents a considerable strain on water treatment installations.[10]

Disposal

Leather biodegrades slowly—taking 25 to 40 years to decompose.[11] However, vinyl and petrochemical-derived materials take 500 or more years to decompose.[12]

Chemical waste disposal

Rajasthani style Leather Jooti,local artwork Jaipur India
Rajasthani-style leather jooti, Jaipur, India

Tanning is especially polluting in countries where environmental regulations are lax, such as in India, the world's third-largest producer and exporter of leather. To give an example of an efficient pollution prevention system, chromium loads per produced tonne are generally abated from 8 kg to 1.5 kg. VOC emissions are typically reduced from 30 kg/t to 2 kg/t in a properly managed facility. A review of the total pollution load decrease achievable according to the United Nations Industrial Development Organization[13] posts precise data on the abatement achievable through industrially proven low-waste advanced methods, while noting, "even though the chrome pollution load can be decreased by 94% on introducing advanced technologies, the minimum residual load 0.15 kg/t raw hide can still cause difficulties when using landfills and composting sludge from wastewater treatment on account of the regulations currently in force in some countries."

In Kanpur, the self-proclaimed "Leather City of World"—with 10,000 tanneries as of 2011 and a city of three million on the banks of the Ganges—pollution levels were so high, that despite an industry crisis, the pollution control board decided to shut down 49 high-polluting tanneries out of 404 in July 2009.[14] In 2003 for instance, the main tanneries' effluent disposal unit was dumping 22 tonnes of chromium-laden solid waste per day in the open.[15]

In the Hazaribagh neighborhood of Dhaka in Bangladesh, chemicals from tanneries end up in Dhaka's main river. Besides the environmental damage, the health of both local factory workers and the end consumer is also negatively affected.[16] After approximately 15 years of ignoring high court rulings, the government shut down more than 100 tanneries the weekend of 8 April 2017 in the neighborhood.[17]

The higher cost associated with the treatment of effluents than to untreated effluent discharging leads to illegal dumping to save on costs. For instance, in Croatia in 2001, proper pollution abatement cost US$70–100 per ton of raw hides processed against $43/t for irresponsible behavior.[18] In November 2009, one of Uganda's main leather making companies was caught directly dumping waste water into a wetland adjacent to Lake Victoria.[19]

Role of enzymes

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 must not damage or dissolve collagen or keratin, but should hydrolyze casein, elastin, albumin, globulin-like proteins, and nonstructural proteins that are not essential for leather making. This process is called bating.[20]

Lipases are used in the degreasing operation to hydrolyze fat particles embedded in the skin.[21]

Amylases are used to soften skin, to bring out the grain, and to impart strength and flexibility to the skin. These enzymes are rarely used.

Preservation and conditioning

The natural fibers of leather 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. Although it is chemically irreversible, treatments can add handling strength and prevent disintegration of red rotted leather.

Exposure to long periods of low relative humidities (below 40%) can cause leather to become desiccated, irreversibly changing the fibrous structure of the leather. Chemical damage can also occur from exposure to environmental factors, including ultraviolet light, ozone, acid from sulfurous and nitrous pollutants in the air, or through a chemical action following any treatment with tallow or oil compounds. Both oxidation and chemical damage occur faster at higher temperatures.

Various treatments are available such as conditioners. Saddle soap is used for cleaning, conditioning, and softening leather. Leather shoes are widely conditioned with shoe polish.[22]

In modern culture

Due to its excellent resistance to abrasion and wind, leather 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.

Leather's flexibility allows it to be formed and shaped into balls and protective gear. Subsequently, many sports use equipment made from leather, such as baseball gloves and the ball used in American football.

Leather fetishism is the name popularly used to describe a fetishistic attraction to people wearing leather, or in certain cases, to the garments themselves.

Many rock groups (particularly heavy metal and punk groups in the 1980s) are well known for wearing leather clothing. Extreme metal bands (especially black metal bands) and Goth rock groups have extensive leather clothing. Leather has become less common in the punk community over the last three decades, as there is opposition to the use of leather from punks who support animal rights.

Many cars and trucks come with optional or standard leather or "leather faced" seating.

Religious sensitivities

In countries with significant populations of individuals observing religions which place restrictions on material choices, leather vendors typically clarify the kinds of leather in their products. For example, leather shoes bear a label that identifies the animal from which the leather came. This helps a Muslim not accidentally purchase pigskin, and a Hindu avoid cattle. Many vegetarian Hindus do not use any kind of leather. Such taboos increase the demand for religiously neutral leathers such as ostrich and deer.

Judaism forbids the comfort of wearing leather shoes on Yom Kippur, Tisha B'Av, and during mourning.[23] Also, see Teffilin and Torah Scroll.

Jainism prohibits the use of leather, since it is obtained by killing animals.

Alternatives

Many artificial leather substitutes have been developed, usually involving polyurethane or vinyl coatings applied to a cloth backing. Many names and brands for such artificial leathers exist, including "pleather", a portmanteau of "plastic leather", and the brand name Naugahyde.[24]

References

  1. ^ NIIR Board of Consultants (2011). Leather Processing & Tanning Technology Handbook. NIIR Project Consultancy Services. p. 323. ISBN 9788190568593.
  2. ^ Binggeli, Corky (2013). Materials for Interior Environments. John Wiley & Sons. p. 119. ISBN 9781118421604.
  3. ^ FAO
  4. ^ International Council of Tanners
  5. ^ "FAQ". Dainese. Retrieved 7 February 2018.
  6. ^ "What type of Leather do I have?". Soccer Cleats 101. Retrieved 27 July 2010.
  7. ^ "Speed Bag Parts". Speed Bag Central. Retrieved 7 February 2018.
  8. ^ Henrylito Tacio,"Why You Should Raise Ostrich," Sun.Star 18 January 2010. Archived 24 December 2013 at the Wayback Machine
  9. ^ Mike Berners-Lee, How Bad are Bananas: The Carbon Footprint of Everything (London: Profile, 2010), p. 201.
  10. ^ "Pollution Prevention and Abatement Handbook - Environmental Guidelines for Tanning and Leather Finishing" (PDF). Multilateral Investment Guarantee Agency, World Bank Group. Retrieved 2 January 2010.
  11. ^ "Interesting Facts about Leather". CalTrend. Retrieved 7 February 2018.
  12. ^ "Why Doesn't Plastic Biodegrade?". LIVESCIENCE. 2 March 2011. Retrieved 7 February 2018.
  13. ^ "The scope for decreasing pollution load in leather processing" (PDF). United Nations Industrial Development Organization Regional Programme for Pollution Control in the Tanning Industry in South-East Asia. 9 August 2000. Retrieved 2 January 2010.
  14. ^ "How much time needed to check tanneries' waste". Times of India. 11 July 2009. Archived from the original on 5 December 2010. Retrieved 2 January 2010.
  15. ^ "Kanpur: chromium disaster". Clean Ganga - Campaign for a cleaner Ganga. June 2003. Archived from the original on 22 August 2003. Retrieved 2 January 2010.
  16. ^ "Hazaribagh neighborhood of Dhaka poisoning staff, local villagers and planet". Human Rights Watch. 8 October 2012. Archived from the original on 28 March 2017. Retrieved 19 November 2016.
  17. ^ "Bangladesh cuts power to leather district after years of environmental violations". PBS NewsHour. Archived from the original on 12 April 2017. Retrieved 11 April 2017.
  18. ^ "Introduction of Low Pollution Processes in Leather Production" (PDF). EcoLinks. 2001. Archived from the original (PDF) on 19 January 2010. Retrieved 2 January 2010.
  19. ^ "Uganda: leather factory faces closure over pollution". The Monitor. 5 November 2009. Archived from the original on 4 June 2011. Retrieved 2 January 2010.
  20. ^ Heidemann, E. (1993). Fundamentals of Leather Manufacture. Eduard Roether KG. p. 211. ISBN 3-7929-0206-0.
  21. ^ Bienkiewicz, K. (1983). Physical Chemistry of Leather Making. Robert E. Krieger. p. 226. ISBN 0-89874-304-4.
  22. ^ "Maintain Lather Bag". larocco. Archived from the original on 3 June 2016. Retrieved 4 May 2016.
  23. ^ "Wearing Shoes - Mourning Observances of Shiva and Sheloshim". Chabad.org. Archived from the original on 22 December 2009. Retrieved 20 October 2009.
  24. ^ "Artificial Leather- An Eco-friendly Alternative Textile Material for leather" (PDF). 2011. Archived from the original on 16 October 2015.

Further reading

Armour

Armour (British English or Canadian English) or armor (American English; see spelling differences) is a protective covering that is used to prevent damage from being inflicted to an object, individual or vehicle by direct contact weapons or projectiles, usually during combat, or from damage caused by a potentially dangerous environment or activity (e.g., cycling, construction sites, etc.). Personal armour is used to protect soldiers and war animals. Vehicle armour is used on warships and armoured fighting vehicles.

A second use of the term armour describes armoured forces, armoured weapons, and their role in combat. After the evolution of armoured warfare, mechanised infantry and their weapons came to be referred to collectively as "armour".

Artificial leather

Artificial leather is a material intended to substitute for leather in upholstery, clothing, footwear, and other uses where a leather-like finish is desired but the actual material is cost-prohibitive or unsuitable. Artificial leather is marketed under many names, including "leatherette", "faux leather", "vegan leather", "PU leather" and "pleather".

BDSM

BDSM is a variety of often erotic practices or roleplaying involving bondage, discipline, dominance and submission, sadomasochism, and other related interpersonal dynamics. Given the wide range of practices, some of which may be engaged in by people who do not consider themselves as practising BDSM, inclusion in the BDSM community or subculture is usually dependent upon self-identification and shared experience.

The term "BDSM" is first recorded in a Usenet posting from 1991, and is interpreted as a combination of the abbreviations B/D (Bondage and Discipline), D/s (Dominance and submission), and S/M (Sadism and Masochism). BDSM is now used as a catch-all phrase covering a wide range of activities, forms of interpersonal relationships, and distinct subcultures. BDSM communities generally welcome anyone with a non-normative streak who identifies with the community; this may include cross-dressers, body modification enthusiasts, animal roleplayers, rubber fetishists, and others.

Activities and relationships within a BDSM context are often characterized by the participants taking on complementary, but unequal roles; thus, the idea of informed consent of both the partners is essential. The terms "submissive" and "dominant" are often used to distinguish these roles: the dominant partner ("dom") takes psychological control over the submissive ("sub"). The terms "top" and "bottom" are also used: the top is the instigator of an action while the bottom is the receiver of the action. The two sets of terms are subtly different: for example, someone may choose to act as bottom to another person, for example, by being whipped, purely recreationally, without any implication of being psychologically dominated by them, or a submissive may be ordered to massage their dominant partner. Despite the bottom performing the action and the top receiving they have not necessarily switched roles.

The abbreviations "sub" and "dom" are frequently used instead of "submissive" and "dominant". Sometimes the female-specific terms "mistress", "domme" or "dominatrix" are used to describe a dominant woman, instead of the gender-neutral term "dom". Individuals who can change between top/dominant and bottom/submissive roles—whether from relationship to relationship or within a given relationship—are known as switches. The precise definition of roles and self-identification is a common subject of debate within the community.

Bear (gay culture)

In male gay culture, a bear is often a larger or obese hairier man who projects an image of rugged masculinity. Bears are one of many LGBT communities with events, codes, and a culture-specific identity. However, in San Francisco in the 1970s any hairy man of whatever shape was referred to as a 'bear' until the term was appropriated by larger men and other words had to be used to describe hairy other-shaped men such as otter (slim), cub (young bear on the way), or wolf (hairy, medium build). The word manatee describes a big, hairless man, i.e. a bear without hair.

The term bear was popularized by Richard Bulger, who, along with his then partner Chris Nelson (1960–2006) founded Bear Magazine in 1987. There is some contention surrounding whether Bulger originated the term and the subculture's conventions. George Mazzei wrote an article for The Advocate in 1979 called "Who's Who in the Zoo?", that characterized gay men as seven types of animals, including bears.

The bear concept can function as an identity or an affiliation, and there is ongoing debate in bear communities about what constitutes a bear. Some bears place importance on presenting a clear masculine image and may disdain or shun men who exhibit effeminacy, while others consider acceptance and inclusiveness of all behavioural types to be an important value of the community.The bear community consists primarily of gay or bisexual men. However, as LGBT culture and modern slang has taken on a wider appeal in modern society, it is possible to call a hairy and burly straight man a bear, although they would not be strictly part of the gay bear community. Increasingly, transgender men (trans men) and those who shun labels for gender and sexuality are also included within bear communities. However, heterosexual men who have bearish physical traits and are affirming of their gay friends and family (or their gay fans, in the case of a celebrity) may also be informally accorded "honorary" bear status. A smaller number of lesbians, particularly those portrayed as butch, also participate in bear culture, referring to themselves with the distinct label of ursula.

Central Leather Research Institute

Central Leather Research Institute or CLRI is the world's largest leather research institute in terms of research papers and patents. The institute located in Chennai, Tamil Nadu was founded on 24 April 1948 as a constituent laboratory under the Council of Scientific and Industrial Research.

Chaps

Chaps ( or ) are sturdy coverings for the legs consisting of leggings and a belt. They are buckled on over trousers with the chaps' integrated belt, but unlike trousers they have no seat and are not joined at the crotch. They are designed to provide protection for the legs and are usually made of leather or a leather-like material. Their name is a shortened version of the Spanish word "chaparreras." Chaparreras were named after the chaparral (thick, thorny, low brush) from which they were designed to protect the legs while riding on horseback. Like much of western horse culture the origin of chaparreras was in Nueva España/New Mexico and has been assimilated into cowboy culture of the American west. They are a protective garment to be used when riding a horse through brushy terrain. In the modern world, they are worn for both practical work purposes and for exhibition or show use. Chaps have also been adopted for use on motorcycles, particularly by Harley riders and other cruiser style motorcycle riders.

Court shoe

A court shoe (British English), coort shoe (Scottish English), or pump (American English), is a shoe with a low-cut front, or vamp, and without a fastening. For the traditional formal menswear, the style is sometimes called an opera slipper or patent leather pump.

The construction of pumps is simple, using a whole-cut leather top with a low vamp, lined with either quilted silk or plain leather, trimmed with braid at the opening. The full leather sole is either glued onto the bottom, common on cheaper styles, or sewn, as on more costly bespoke styles still made traditionally, using a shallow slit to lift a flap of leather around the edge to recess and hide the stitching. The sole is, as on ordinary shoes, several layers of leather put together. The bow is made of grosgrain silk or rayon, in a pinched or flat form.

For women, pumps with a strap across the instep are called Mary Janes. Pumps may have an ankle strap.

Fendi

Fendi (Italian pronunciation: [ˈfɛndi]) is an Italian luxury fashion house producing fur, ready-to-wear, leather goods, shoes, fragrances, eyewear, timepieces and accessories. Founded in 1925 in Rome, Fendi is renowned for its fur and fur accessories. Fendi is also well known for its leather goods such as "Baguette", 2jours, Peekaboo or Pequin handbags.

Football (ball)

A football is a ball inflated with air that is used to play one of the various sports known as football. In these games, with some exceptions, goals or points are scored only when the ball enters one of two designated goal-scoring areas; football games involve the two teams each trying to move the ball in opposite directions along the field of play.

The first balls were made of natural materials, such as an inflated pig bladder, later put inside a leather cover, which has given rise to the American slang-term "pigskin". Modern balls are designed by teams of engineers to exacting specifications, with rubber or plastic bladders, and often with plastic covers. Various leagues and games use different balls, though they all have one of the following basic shapes:

a sphere: used in association football and Gaelic football

a prolate spheroid

either with rounded ends: used in the rugby codes and Australian football

or with more pointed ends: used in American football and Canadian footballThe precise shape and construction of footballs is typically specified as part of the rules and regulations.

The oldest football still in existence, which is thought to have been made circa 1550, was discovered in the roof of Stirling Castle, Scotland, in 1981. The ball is made of leather (possibly from a deer) and a pig's bladder. It has a diameter of between 14–16 cm (5.5–6.3 in), weighs 125 g (4.4 oz) and is currently on display at the Smith Art Gallery and Museum in Stirling.

Glove

A glove (Middle English from Old English glof) is a garment covering the whole hand. Gloves usually have separate sheaths or openings for each finger and the thumb.

If there is an opening but no (or a short) covering sheath for each finger they are called fingerless gloves. Fingerless gloves having one large opening rather than individual openings for each finger are sometimes called gauntlets, though gauntlets are not necessarily fingerless.

Gloves which cover the entire hand or fist but do not have separate finger openings or sheaths are called mittens. Mittens are warmer than other styles of gloves made of the same material because fingers maintain their warmth better when they are in contact with each other; reduced surface area reduces heat loss.

A hybrid of glove and mitten contains open-ended sheaths for the four fingers (as in a fingerless glove, but not the thumb) and an additional compartment encapsulating the four fingers. This compartment can be lifted off the fingers and folded back to allow the individual fingers ease of movement and access while the hand remains covered. The usual design is for the mitten cavity to be stitched onto the back of the fingerless glove only, allowing it to be flipped over (normally held back by Velcro or a button) to transform the garment from a mitten to a glove. These hybrids are called convertible mittens or glittens, a combination of "glove" and "mittens".

Gloves protect and comfort hands against cold or heat, damage by friction, abrasion or chemicals, and disease; or in turn to provide a guard for what a bare hand should not touch. Latex, nitrile rubber or vinyl disposable gloves are often worn by health care professionals as hygiene and contamination protection measures. Police officers often wear them to work in crime scenes to prevent destroying evidence in the scene. Many criminals wear gloves to avoid leaving fingerprints, which makes the crime investigation more difficult. However, the gloves themselves can leave prints that are just as unique as human fingerprints. After collecting glove prints, law enforcement can then match them to gloves that they have collected as evidence. In many jurisdictions the act of wearing gloves itself while committing a crime can be prosecuted as an inchoate offense.Fingerless gloves are useful where dexterity is required that gloves would restrict. Cigarette smokers and church organists often use fingerless gloves. Some gloves include a gauntlet that extends partway up the arm. Cycling gloves for road racing or touring are usually fingerless. Guitar players often use fingerless gloves in circumstances where it is too cold to play with an uncovered hand.

Gloves are made of materials including cloth, knitted or felted wool, leather, rubber, latex, neoprene, silk, and metal (as in mail). Gloves of kevlar protect the wearer from cuts. Gloves and gauntlets are integral components of pressure suits and spacesuits such as the Apollo/Skylab A7L which went to the moon. Spacesuit gloves combine toughness and environmental protection with a degree of sensitivity and flexibility.

Helmet

A helmet is a form of protective gear worn to protect the head. More specifically, a helmet complements the skull in protecting the human brain. Ceremonial or symbolic helmets (e.g. UK policeman's helmet) without protective function are sometimes worn. Soldiers wear helmets, often made from lightweight plastic materials.

The word helmet is diminutive from helm, a medieval word for protective combat headgear. The medieval great helm covers the whole head and often is accompanied with camail protecting throat and neck as well. Originally a helmet was a helm which covered the head only partly and protected it from injury in accidents.

In civilian life, helmets are used for recreational activities and sports (e.g. jockeys in horse racing, American football, ice hockey, cricket, baseball, camogie, hurling and rock climbing); dangerous work activities (e.g. construction, mining, riot police); and transportation (e.g. motorcycle helmets and bicycle helmets). Since the 1990s, most helmets are made from resin or plastic, which may be reinforced with fibers such as aramids.

History of hide materials

Humanity has used animal hides since the Paleolithic, for clothing as well as mobile shelters such as tipis and wigwams, and household items. Since ancient times, hides have also been used as a writing medium, in the form of parchment.

Fur clothing was used by other hominids, at least the Neanderthals.

Rawhide is a simple hide product, that turns stiff. It was formerly used for binding pieces of wood together. Today it is mostly found in drum skins.

Tanning of hides to manufacture leather was invented during the Paleolithic.

Parchment for use in writing was introduced during the Bronze Age and later refined into vellum, before paper became commonplace.

Jack the Ripper

Jack the Ripper is the best-known name for an unidentified serial killer generally believed to have been active in the largely impoverished areas in and around the Whitechapel district of London in 1888. In both the criminal case files and contemporary journalistic accounts, the killer was called the Whitechapel Murderer and Leather Apron.

Attacks ascribed to Jack the Ripper typically involved female prostitutes who lived and worked in the slums of the East End of London whose throats were cut prior to abdominal mutilations. The removal of internal organs from at least three of the victims led to proposals that their killer had some anatomical or surgical knowledge. Rumours that the murders were connected intensified in September and October 1888, and letters were received by media outlets and Scotland Yard from a writer or writers purporting to be the murderer. The name "Jack the Ripper" originated in a letter written by someone claiming to be the murderer that was disseminated in the media. The letter is widely believed to have been a hoax and may have been written by journalists in an attempt to heighten interest in the story and increase their newspapers' circulation. The "From Hell" letter received by George Lusk of the Whitechapel Vigilance Committee came with half of a preserved human kidney, purportedly taken from one of the victims. The public came increasingly to believe in a single serial killer known as "Jack the Ripper", mainly because of the extraordinarily brutal nature of the murders, and because of media treatment of the events.

Extensive newspaper coverage bestowed widespread and enduring international notoriety on the Ripper, and the legend solidified. A police investigation into a series of eleven brutal killings in Whitechapel up to 1891 was unable to connect all the killings conclusively to the murders of 1888. Five victims—Mary Ann Nichols, Annie Chapman, Elizabeth Stride, Catherine Eddowes, and Mary Jane Kelly—are known as the "canonical five" and their murders between 31 August and 9 November 1888 are often considered the most likely to be linked. The murders were never solved, and the legends surrounding them became a combination of genuine historical research, folklore, and pseudohistory. The term "ripperology" was coined to describe the study and analysis of the Ripper cases. There are now over one hundred hypotheses about the Ripper's identity, and the murders have inspired many works of fiction.

Leather crafting

Leather crafting or simply leathercraft is the practice of making leather into craft objects or works of art, using shaping techniques, coloring techniques or both.

Leather jacket

A leather jacket is a jacket-length coat that is usually worn on top of other apparel or item of clothing, and made from the tanned hide of various animals. The leather material is typically dyed black, or various shades of brown, but a wide range of colors is possible. Leather jackets can be designed for many purposes, and specific styles have been associated with subcultures such as greasers, rednecks, cowboys, motorcyclists, military aviators, mobsters, police, secret agents, and music subcultures (punks, goths, metalheads, rivetheads), who have worn the garment for protective or fashionable reasons, and occasionally to create a potentially intimidating appearance. National Leather Jacket day occurs every June 14th since the Hell's Angels proposed the idea in 1975.

Most modern leather jackets are produced in Pakistan, India, Canada, Mexico and the United States, using hides left over from the meat industry. Fabrics simulating leather such as polyurethane or PVC are used as alternatives to authentic animal hide leather depending on the needs of the wearer such as those pursuing vegan lifestyles or for economic reasons as synthetic fibers tend to be less costly than authentic leather.

Leather subculture

The leather subculture denotes practices and styles of dress organized around sexual activities that involve leather garments, such as leather jackets, vests, boots, chaps, harnesses, or other items. Wearing leather garments is one way that participants in this culture self-consciously distinguish themselves from mainstream sexual cultures. Many people associate leather culture with BDSM (Bondage/Discipline, Dominance/Submission, Sado/Masochism, also called "SM" or "S&M") practices and its many subcultures. But for others, wearing black leather clothing is an erotic fashion that expresses heightened masculinity or the appropriation of sexual power; love of motorcycles, motorcycle clubs and independence; and/or engagement in sexual kink or leather fetishism.

Parchment

Parchment is a writing material made from specially prepared untanned skins of animals—primarily sheep, calves, and goats. It has been used as a writing medium for over two millennia. Vellum is a finer quality parchment made from the skins of young animals such as lambs and young calves.

It may be called animal membrane by libraries and museums that wish to avoid distinguishing between "parchment" and the more-restricted term vellum (see below).

Shoemaking

Shoemaking is the process of making footwear.

Originally, shoes were made one at a time by hand. Traditional handicraft shoemaking has now been largely superseded in volume of shoes produced by industrial mass production of footwear, but not necessarily in quality, attention to detail, or craftsmanship.

Shoemakers (also known as cordwainers) may produce a range of footwear items, including shoes, boots, sandals, clogs and moccasins. Such items are generally made of leather, wood, rubber, plastic, jute or other plant material, and often consist of multiple parts for better durability of the sole, stitched to a leather upper

Trades that engage in shoemaking have included the cordwainer's and cobbler's trades. Today, shoes are often made on a volume basis, rather than a craft basis.

Tanning (leather)

Tanning is the process of treating skins and hides of animals to produce leather. A tannery is the place where the skins are processed.

Tanning hide into leather involves a process which permanently alters the protein structure of skin, making it more durable and less susceptible to decomposition, and also possibly coloring it.

Before tanning, the skins are unhaired, degreased, desalted and soaked in water over a period of 6 hours to 2 days. Historically this process was considered a noxious or "odoriferous trade" and relegated to the outskirts of town.

Traditionally, tanning used tannin, an acidic chemical compound from which the tanning process draws its name (tannin is in turn named after an old German word for oak or fir trees, from which the compound was derived). The use of a chromium (III) solution was adopted by tanners in the Industrial Revolution.

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