leather - Forms of leather, Preservation and conditioning of leather, Working with leather, Main manufactures, Cordwain

Animal skin rendered durable and resistant to wear and degeneration by tanning. The skin is limed to remove hair, cleaned of flesh, and then soaked in solutions of extracts of bark, galls, or other vegetable products which contain tannins (tannic acids widely distributed in nature) or chrome salts. It is finished mechanically according to use. The properties of leather are due to its fibrous and porous structure, and to its resistance to deterioration on repeated wetting and drying. Morocco leather is a goat skin, repeatedly polished. Chamois leather was originally from the chamois deer, but most is now from other skins split and tanned for softness. Synthetic materials with a porous structure resembling leather are now made.

For people named Leather, see Leather (surname).

Leather is a material created through the tanning of hides, pelts and skins of animals, primarily cows. Leather is a very important clothing material, and its other uses are legion.

Forms of leather

There are a number of processes whereby the skin of a dead animal can be formed into a supple, strong material commonly called leather. Vegetable-tanned leather is not stable in water; 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. 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 heads where it does not need to flex significantly; Boiled leather is a hide product (vegetable-tanned leather) that has been hardened by being immersed in hot water, or in boiled wax or similar substances. It is more supple and pliable than vegetable-tanned leather, and does not discolor or lose shape as drastically in water as vegetable-tanned. 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.

For further information on the production of leather see tanning.

Leather types

In general, leather is sold in three forms:

Full-Grain leather, made from the finest raw material, are clean natural hides which have not been sanded to remove imperfections. The natural Full-Grain surface will wear better than other leather. The finest furniture, and footwear, are made from Full Grain leather. Corrected-Grain leather, also known as Top-Grain leather, is fuzzy on one side and smooth on the other. Top grain leather generally must be heavily painted to cover up the sanding and stamping process.

Other less-common leathers include:

Buckskin or brained leather is a tawing process that uses animal brains or other fatty materials to alter the leather. Patent leather is leather that has been given a high gloss finish. 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.

There are two other descriptions of leather commonly used in speciality 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. 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. Napa leather, or Nappa leather, 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.

Bicast leather is man-made product that contains some amount of leather. 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.

Leather is sold in a variety of thicknesses. 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. Other leather manufacturers state the thickness directly in millimetres.

Leather from other animals

Today, most leather is made of cow hides, but many exceptions exist. Lamb and deer skin are used for soft leather in more expensive apparels. Kangaroo leather is used to make items which need to be strong but flexible, such as motorcycle gloves. Kangaroo leather is favored by motorcyclists specifically because of its lighter weight and higher abrasion resistance as compared to cowhide. Leather made from more exotic skins has at different times in history been considered very beautiful. As a side product, ostrich leather became available. Ostrich leather is considered to be of the finest and most durable in the world and is currently used by all the big fashion houses like Hermès, Prada, Gucci, and Louis Vuitton.

In Thailand, sting ray leather is used in wallets and belts in the same way as regular cow leather. The leather is often dyed black and covered with tiny round bumps in the natural pattern of the back ridge of an animal.

Preservation and conditioning of leather

The natural fibers of leather will break down with the passage of time.

Exposure to long periods of low relative humidities (below 40%) can cause leather to become desiccated, irreversably changing the fibrous structure of the leather.

Various treatments are available such as conditioners, but these are not recommended by conservators since they impregnate the structure of the leather artifact with active chemicals, are sticky, and attract stains.

Working with leather

Leather can be decorated by a variety of methods, including:

leather dying leather painting leather carving leather stamping leather embossing pyrography beading

Main manufactures

Solofra city, located in Italy

Cordwain

Painted or 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').

Leather in modern culture

Leather, due to its excellent abrasion and wind resistance, found a use in rugged occupations. 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 metonymical term for things 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.

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

A number of rock groups, particularly Heavy Metal groups such as Scorpions and Judas Priest, are well-known for wearing leather clothing (although Rob Halford of Judas Priest wears a synthetic material he invented, instead of leather). This can range from cheap vinyl material, found on some low cost vehicles, to Napa leather, found on luxury car brands like Mercedes-Benz.

Concern for animals and alternatives

Some vegan and animal rights activists have boycotted use of all leather items, believing the practice of wearing skins unnecessary and vulgar in today's society.

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.