Clamp money tin ingot currency

Clamp money — known in Thai as "ngoen khip" — circulated across mainland Southeast Asia for several centuries as a practical trade medium in regions where Chinese cast coinage and later European specie were either scarce or refused. The folded, pinched form was not ornamental; it allowed rapid tactile verification of the metal without scales, and stacks could be bundled efficiently for transport along riverine trade routes connecting Lan Na, the Shan states, and the upper Mekong corridor.

Tin was the dominant monetary metal in this zone precisely because the peninsula sat atop some of the world's most productive alluvial tin deposits. Assigning a tight date range to individual specimens remains difficult — production was decentralized, unregulated, and continued in some areas well into the nineteenth century.