1/n
In 2014, a group of 9 Indus copper plates ( 2600 BCE), discovered in a private collection in Pakistan, revealed an incredible secret. The plates proved that printing was first invented in India more than 1500 years before the first known printing, in China around 700 BCE.
2/n
Authors Vasant Shinde & Rick J Willis wrote a detailed scientific paper discussing the discovery & its implications. The plates are larger and stronger than known copper plates or tablets, but the most significant detail is that they are inscribed with mirrored characters.
3/n
One of the plates bears 34 characters, which is the longest known single Indus script inscription. A thorough examination revealed the copper plates were not used as seal but as templates for copper plate printing. This makes them the earliest known printing devices, by far.
4/n
In their paper, Shinde & Willis write:
"They are quite different from other metal plates or tablets recovered from Mohenjo-daro & Harappa, as they are larger and much thicker, but most significantly they bear inscriptions only on one surface and the script is reversed. “
5/n
“Data from all tests, including x-ray fluorescence metal analyses, conventional and scanning electron microscopy, and metallographic analysis are totally consistent with metal artifacts from Indus Valley (Harappan) civilization, c. 2600–2000 BC.”