Hides and Skins

the skins of domestic and wild animals, as well as fur seals, fish, and reptiles, that are used as the raw materials in making leather.

The suitability of a skin for making a particular type of leather, as well as the peculiarities of the manufacturing process, is determined by the skin’s thickness and the uniformity of thickness over its area; by its size, weight, and density; by the thickness of the epidermis and degree of development of the hair covering; by the ratio of the papillose and reticulate layers of the dermis; by the nature of the interlacing of fibers, the thickness and condition of the subcutaneous cells, the peculiarities and degree of development of the surface components, and the chemical composition and properties of the protein substances; and by the presence of defects. These factors are influenced by the origin of the animal (species, breed, sex, and age) and the conditions of its life (climate, captivity, and feeding), the time and method of slaughtering the animal (skins taken from animals that died naturally are of significantly lower quality), the method of removing the skin from the carcass, and the dressing, preserving, and storing of the skin. During slaughter, the animal must be bled to the maximum. Blood remaining in the blood vessels of the skin lowers its quality.

A hide or skin just taken from the animal is called fresh. It cannot be kept in that condition for more than two hours. During this time the skin is dressed (removal of bits of flesh and fat, remains of cartilage, bone, tendons, horns, hooves, and tail heads) and cleaned, after which it is preserved, collected in production batches, and stored. A distinction is made between common defects, found in skins of various types, and specific defects, belonging only to certain types of hides and skins.

A distinction is made among skins, hides, and pigskin. Skins come from calves, foals, sheep, goats, and other small animals (young camels and seals). Hides are the skins of cattle, horses, donkeys, camels, deer, elk, walruses, and whales. Pigskin raw materials are the skins of domestic and wild swine. In addition to these most important types of leather raw materials, the skins of reptiles (crocodiles, lizards, and snakes) and fish (wolf-fish, cod, burbot, sheatfish, dog salmon, giant sturgeon, and shark) are also used.

Skins are used to make leather for shoe uppers, clothing, and haberdashery. Hides (the finer and lighter hides, as well as some of medium size) are used to make chrome-tanned leather for shoe uppers, Russia leather, harness and saddle leathers, welt leather and shoe bottoms, and industrial leather. Heavy pigskin is also used for this purpose.

Evaluation of the quality of hides and skins is done by organoleptic, microbiological, histological, and chemical methods. An important characteristic of hides and skins is their large share in the prime cost of the leather (about 65–70 percent); therefore, the basic means for lowering the prime cost of production in leather factories is associated with better use of the raw materials.