Before the Double 7th Incident (July 7, 1937) postage stamps were either printed by the Peiping Printing Bureau of the Ministry of Finance, or by the Thomas de la Rue & Co., Ltd. in England. Beginning in 1938 following the outbreak of the War of Resistance against Japan the stamps were all ordered from Hongkong.
The Chung Hwa Book Co., Hongkong started to print Dr. Sun Yat-sen stamps of three denominations ($1, $2, $5) in intaglio and bi-color. In a narrow horizontal panel above the national emblem are several perpendicular short lines in the middle with a blank space on the sides(P-29). Such stamps are commonly known as 〝Blank Panel Stamps.〞
In the $1, $2 and $5 stamps printed in the first batch, only a half circle of the button on the coat is visible. In the one and two dollar denominations printed in the second batch, the full circle of the button is shown. According to the amount of the button shown, these stamps are called 〝Half Button〞or〝Full Button〞stamps.