These were obsolete revenue stamps purchased from the Ministry of Finance. The overprint was done by the Central Engraving & Printing Works, Taipei by the offset process. The overprint〝中華民國郵政〞(Postal Administration of the Republic of China) and 〝欠資臺幣面值〞(postage-due： denomination Taiwan currency) appears in two horizontal lines over the central design and in Arabic figures at the bottom. Among such obsolete revenue stamps, those of the $100 and $500 denominations which were originally printed in intaglio, were specially overprinted with a plate covering 25 pieces, due to the difficulty of overprinting paper shrunk by moisture.