The original colors used in Japanese buildings were those obtained from natural materials, timber with bark (black) or stripped timber (white) and clay walls. Over the course of time, China and Korea influenced the use of polychromy, but the selection of colors was limited to the availability of inorganic pigments. Cochineal, however, was used to produce a deep red. In the evolution of the building structure, the raised floor provided a barrier in protecting paintings from rising damp . Historically, the use of polychrome, tapestry, metalwork, lacquer, and clay for the decoration of building interiors reflected religious and political influences. The teahouse recalls the earliest use of natural materials.