One of the most important sources of history in the Indian subcontinent are the royal records of grants engraved on copper-plates (tamra-shasan or tamra-patra; tamra means copper in Sanskrit and several other Indian languages). Because copper does not rust or decay, they can survive virtually indefinitely.
Collections of archaeological texts from the copper-plates and rock-inscriptions have been compiled and published by the Archaeological Survey of India during the past century.
Approximate dimensions of Copper Plate is 9 3/4 inch long x 3 1/4 inch high x 1/10 (to 1/16) inch thick.
The earliest known copper-plate known as the Sohgaura copper-plate is a Maurya record that mentions famine relief efforts. It is one of the very few pre-Ashoka Brahmi inscriptions in India.