Air 7 Shanghai Surcharged Air Mail Stamps (1948)

　　As the fluctuation of the national currency in 1948 necessitated the issue of high-value air mail stamps to meet the public requirement, the air mail stamps of all prints then still in stock were overprinted in higher values by the Dah Yeh Printing Press, Shanghai (上海大業印刷公司) in red or black by the typography process. Due to the differences in the size and design of the stamps, the overprint was done in two ways as described below：

　　(1)3rd Peiping Print and Honkong Print . The Chinese characters and Arabic figures were both overprinted horizontally in the center of the stamps, and the original face value was deleted by double-lined cross`like marks.

　　(2) Shanghai Print .The Chinese characters were overprinted in a vertical line near the right side, and the Arabic numerals were overprinted over the original value in the lower left corner.