Cultural developments that already can be seen in Shang times took more shape to found a unique Chinese style. Art objects became more practical for the daily life; Heaven was mere seen as an approving or disapproving instance (in that case sending flood, drought, earthquakes and sun eclipses), the compound of buildings and the bureaucratic state are already parts of the traditional and uniform Chinese state, thinking and art. The Western Zhou Dynasty thus served as a model for the rest of Chinese imperial history, claiming a unity where there was actually a cultural and ethnic diversity. During the Warring States Period, the art of bronze casting was made perfect by the lost-wax techniques (see the perfect art of bronze casting in the examples of vessels of the tomb No. II of Marquis Zeng 曾侯乙墓). Vessels inlaid with gold and silver became popular, new motifs were used, and bronze was first used for items like mirrors or candle holders. Pictorial art became a new tool of decoration of bronze and lacquered objects and for mural painting. For the first time, silk was used as a material for writing and to draw pictures on.