Bark

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Bark, hard covering or rind of the stem, branches, and roots of a tree or other plant, as distinguished from the wood. The bark consists of an inner and outer layer. Bark is used commercially in the tanning of leather, in boatbuilding, and in basket making and in the manufacture of clothing and shoes, food flavoring, medicine, and cork and cork products.

Barks rich in tannin are usually used for tanning, although other properties also determine the value of a bark for preparing leather. Bark from several species of oak in the genus Quercus and from the Eastern hemlock (Tsuga canadensis) used to supply much of the tannin in the northern United States. In recent years, however, use of the wood or fruit of many other trees and the development of synthetic tannins have replaced earlier sources.

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