Bark is a somewhat rare facade material made from the outer tissue of woody plants. It is most often taken from tree trunks and flattened into tiles or shingles. It often has an extremely rough appearance, and may be used to add texture for aesthetic purposes.

Bark is the plant's outer covering. It differs from wood taken from the material beneath that covering.

Flattened pieces can cover the exterior as tiles or shingles while retaining a rough surface texture. The surface arrangement and the bark material are separate characteristics.