The art of khruang thorn , as the Thais call nielloware, is believed lo have come to the country during the Ayutthaya period . The precise origin is uncertain; some scholars say it came from China, while others give Persia as the source. In any case, it became a popular craft in southern Thailand, particularly in Nakhon Si Thammarat , and is still produced there.

Fine nielloware is usually made of pure silver, sometimes later plated with gold. The metal is bought by the craftsmen in thin sheets, from which the desired shape is cut and welded into a crude, three -dimensional form. After the design has been engraved - usually traditional, such as Thai flame or an intricate floral motif - an oxidizing solution is applied to the pans in high relief, turning them a permanent blue black. The piece is ihen filed to remove all the rough edges and given a final polishing. Nielloware objects have been made in almost every conceivable shape, from elaborate coffee and tea sets to handbags and buttons. It is one of Thailand 's most distinctive and beautiful crafts.