Leather

What is leather?

Leather is one of a range of manufactured materials which can be made from the skin of any animal.

Long before genuine tanning methods were used to prepare leather, hides and skins were processed in a variety of ways. The different processes were all designed to preserve the skins; and each process produced skin products with different properties. Working oil, grease and even brain matter into raw skins, softening hides by chewing them and smoking skins were some of the processes used. These methods affected both the look and feel of skins and their resistance to deterioration.

Technically, the term 'leather' refers to skin products which have been fully tanned. Tanning is a process which chemically alters skins, making them more durable and more resistant to rotting. It does this by chemically linking relatively small molecules and fibres in the original skins into groups of larger molecules and fibres. Large molecules take longer to break down than smaller ones.

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Some of the other skin-processing methods also link fibres and result in larger molecules; but none of them do it as fully as the various tanning techniques, and none of them produce a material as durable as leather. Other skin products include rawhide, parchment and vellum, and semi-tanned leather.

Leather is made up of tanned collagen—the protein which makes up skin and bones—moisture, oils and fat.

Leather in good condition is naturally acidic: in the range of pH 3–6, with a water content of between 12–20% and a fat content in the range 2–10%.