Leather is a material created through the tanning of hides and skins of animals, primarily cattlehide. 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 glue and gelatin.  Frequent oiling of leather, with mink oil, neatsfoot oil or a similar material, keeps it supple and improves its lifespan dramatically.

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 (or natural marks) 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 change in its appearance 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 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 created from the fibrous part of the hide left once the top-grain of the rawhide 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.
• Leather from other animals
  

  

  Tanned leather in Marrakech
  

  

  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 saddles.

  Kangaroo skin is used to make items which need to be strong but flexible, it is the material most commonly used in high quality bullwhips. Kangaroo leather is favored by some motorcyclists for use in motorcycle leathers specifically because of its lighter weight and higher abrasion resistance compared with cowhide, thus providing greater protection 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 snakes and crocodiles 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.

• 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 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.

• Mink oil, leather treatment
• Neatsfoot oil, leather treatment
• Saddle soap, leather cleaning and conditioning