In the old days, the paper used by the Hongkong Post for printing stamps contained a watermark to protect against counterfeiting. By the 1990s, this paper had begun to incorporate security fibres, while phosphor tagging techniques and fluorescent ink are now used as security features replacing the watermark. Advances in printing techniques have also enhanced the efficiency of mail handling. The Hongkong Post introduced Culler-Facer-Canceller machines in 1996, which sort the mail into local and overseas groups and cancel the stamps in accordance with their phosphor tags. The stamps commemorating the opening of the Centennial Olympics in Atlanta issued that same year were the first to be printed with this phosphor label.

The stamps issued in 2001 to celebrate 150 years of the city’s water supply were the first embossed stamps in Hong Kong; special spot varnishing was used to highlight and reflect the water droplet motif and to enhance the water’s translucent and flowing quality. The ‘Rocks of Hong Kong’ special stamps issued in 2002 used thermography printing techniques to lend the stamps a surface coating resembling the coarseness of rocks. In 2003, Hong Kong and Sweden joined hands to issue a set of special stamps showcasing four water birds that can be found in the two regions, with Sweden Post Stamps printing the stamps using both intaglio and lithography processes to enrich the detailed appearance of the birds.