Hides and Skins: Unravelling Nature’s Marvel

The emergence of skin during evolution in the animal kingdom is one of nature’s marvels. Emerging in an identifiable form in primitive fish, evolution continued to improve the structure such that when mammals emerged and further developed, they had complex hides, skins and furs. Early in hominid evolution, and with the development of tools, people realised the value of these by-products of hunting in providing shelter, clothing and protection. These early steps led to the basis of the now well-established leather industry and its diverse product applications. This industry is still based on by-products, mainly of the global food (meat) industry, utilising material that mostly would otherwise go to landfill. The utility and advantages of leather include its durability, breathability and visco-elastic characteristics, as well as the intangible but important aesthetic qualities. These unique properties derive from the composition and structure of skin. The principle structural components of skin are many members of the collagen family of proteins, particularly types I and III collagens. Skin comprises several structurally distinct zones. Outermost is the epidermis which is lost during tanning; this leaves a surface derived from a basement membrane that provides the valuable grain surface of leather. Beneath this is the papillary dermis, which is home to hair and sebaceous glands, and further in the depth is the reticular dermis (corium) that is comprised principally of type I collagen and provides the bulk of the skin. Detailed studies of the structure and functions of collagen and its fibres, along with stability and crosslinking properties, have continually led to a better understanding of the tanning process, and contributed to on-going improvements in quality, environment and value. The future for leather looks bright, with many infomediaries predicting strong growth, assisted by improved processes and products.