Published online by Cambridge University Press: 28 February 2011
Technical studies were performed on one hundred and seven Chinese copper-alloy sculptures dating from the fifth to the nineteenth centuries A. D. in the collection of the Freer Gallery of Art. X-radiography, stereomicroscopy and metallography were used to determine various physical features; atomic absorption spectroscopy was used to characterize the metal composition. All sculptures were determined to be cast by the lost wax method, and details were tooled by engraving and chasing. Metallographic examination and microprobe analysis showed that the gilding technique used was mercury gilding. Bronzes from the Northern Wei to the Song dynasty are similar in their physical characteristics and alloy type, leaded tin bronze. Beginning in the Ming dynasty, an increase in the amount of zinc is found, both as an impurity in tin bronzes and as a brass alloy constituent.