![]() The type of wool the sheep produces determines what the skin and leather cross sections will look like. Sheep skin leather sometimes includes the wool, and this may be a useful clue to what species of mammal the skin is from. Corium fiber bundles are fairly fine and the difference between the grain and corium layers is rather indistinct ( Haines 2006, 14). Goat skins range in thickness between 1 and 3mm, and the grain layer takes up a greater portion of the skin (about a third of its thickness) than the grain layer in cow skin. While calf skin and leather has the same structure as adult skin, the corium layer is much thinner and has finer bundles of fibers ( Haines 2006, 14). ( Haines 2006, 13).Skin and leather from calves is thinner than adult skin, but becomes thicker with age. Cross section of mature cattle skin leather. The corium layer consists of thick fibers, which resemble a tangled mass beneath the grain layer.Figure 5. The grain layer, which constitutes the outer portion of the skin, contains hairs that are equally spaced ( Haines 2006, 13). Mature cow skins are thicker, usually between 4 and 6 mm ( Haines 2006, 12). In leather made from cattle, the nature of the skin changes depending on the age of the cattle. Under greater magnification, cross sections of the leather in questioncan reveal the configuration of the collagen layers, which can be diagnostic of the species from which the leather came. Like goat skin, the follicles of sheep skin are arranged in clusters ( Haines 2006, 19).Ĭollagen configuration Leather from goat skin has alternating rows of large and fine hair follicles that form clusters.The follicles in sheep skin leather are all the same size and are relatively small. No matter the age of the animal from which the leather comes, the follicle pattern will be the same. Calfskin follicles are smaller and closer together, and adult cattle skin has larger follicles. Leather from cattle skin has hair follicles that are mostly “equal in size and arranged in regular rows” ( Haines 2006, 17). These two characteristics are sometimes good indicators of the animal that the leather came from. With a microscope or even a loupe, the conservator can sometimes discern how the grain and hair follicle pattern is arranged. Perhaps the easiest method of identifying leather is by looking at it under magnification. The grain, hair follicle pattern, collagen fiber configuration, use of the leather, and infrared spectroscopy can offer clues to what animal the leather came from. Despite this manipulation, identification of the type of skin the conservator is preserving may still be possible. Many aspects can alter the appearance of animal skin leather such as tanning, leather treatments, and deterioration from use or burial. If appropriate: brief summary or introduction to historical context, art historic background, function, use, etc. The materials and technologies for the final products are found in the following sections. Decoration and protective coatings are often applied. Untanned and cured products can be manipulated by processes such as cutting or sewing. Various procedures are carried out to prevent purification and impart specific working properties to the finished product. ![]() All of these animal products are composed of the protein collagen. The raw materials for skin and leather products are obtained from a wide range of animals. 2.3 Interventive treatments for Leather and Semi-tanned Hide/Fur.1.3.2 Deterioration of Waterlogged Archaeological Leather.1.3.1 Deterioration of Patent Leather Coatings.
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