Illustrations by the artist, commissioned for The Times in 1962, were sculpted on spuds before being stamped onto paper.

Today, more than a dozen stalls specialising in stamps still line the alley ... of the owners still making stone seals by hand. Seal carving dates back to the Spring and Autumn period in China ...

In 2014, Hong Kong added Chinese seal engraving to its Intangible Cultural Heritage Inventory, five years after Unesco listed the art ... of the stamps, which often features intricate carvings ...