Birch bark

Birch bark or birchbark is the bark of several Eurasian and North American birch trees of the genus Betula.

For all practical purposes, birch bark's main layers are the outer dense layer, white on the outside, and the inner porous layer (cambium). For vast majority of crafts, the outer bark is used. In many languages it has a separate name. For example, in Russian "birch bark" is "beryozovaya kora", while the outer birch bark is "beryosta".

The strong and water-resistant cardboard-like outer bark can be easily cut, bent, and sewn, which has made it a valuable building, crafting, and writing material, since pre-historic times. Today, birch bark remains a popular type of wood for various handicrafts and arts.

Birch bark also contains substances of medicinal and chemical interest. Some of those products (such as betulin) also have fungicidal properties that help preserve bark artifacts, as well as food preserved in bark containers.