Top: Chen Shaohua, designer of the 2012 dragon zodiac stamp, defends his design. Shang Hongtao / for China Daily Center: The 12 stamps of the first set of Chinese zodiac signs from 1980 to 1992. Above: The Year of the Tiger in 2010 featured an updated tiger with hands on hips, while the more traditional dragon ruled on a postage stamp issued in France. [Photo/China Daily]

A set of 80 dragon stamps from 1988 sells for about 3,000 yuan now, while a set of 32 stamps from 2000 is valued at more than 5,000 yuan.

Geng Shouzhong, author of the international award-winning Encyclopedia Knowledge of Chinese Philately, explains that in 2000, the Year of the Dragon coincided with a significant year in the Gregorian calendar, and many Chinese used the dragon stamps to post letters to mark the occasion. That left a limited number of mint-condition stamps, those valued most by traders and collectors.

Geng, with his 60 years of stamp-collecting experience, believes the price hike of the newly released dragon stamps is a mirage, as it is still untested by time.

Above all, Geng says the ultimate value of the stamp depends on how many were produced and how many tradable units are left over time.

These are the two main factors that help create valuable "legendary" stamps.

The monkey zodiac stamp released in 1980 was the first in the series released in China. Each monkey stamp can now fetch more than 10,000 yuan, and a complete set of 80 stamps will easily cost more than one million yuan.

It was at a time when the country was recovering from a "cultural revolution" (1966-76) and stamp collectors were only beginning to start up their hobby again. For that reason, the print-run was kept conservative and was to be only 6 million.

However, printing ink ran out sooner than expected and as a result, only 5 million monkey zodiac stamps were printed, Geng remembers. After further eliminating stamps that were of poor quality, the number of monkey zodiac stamps that finally showed up on the market was only about 4 million - the lowest number in the zodiac series to this day.

Since then, as public demands for these annual collectibles increased, the print numbers went up in response.