The Story of India’s Indelible Ink A testament to the power of science in service of society



In 1950, as India took its first step as a fledgling democracy, ensuring fair and free elections posed a significant challenge. Amidst concerns about fraudulent voting, the Council of Scientific and Industrial Research (CSIR) stepped forward with a mission to find a scientific solution to safeguard the democratic process.

At the helm of this endeavour was the Ink Development Unit (IDU) at the CSIR-National Physical Laboratory (CSIR-NPL), New Delhi, led by Dr Salimuzzaman Siddiqui. Initially focused on manufacturing postal stamping ink, the IDU soon pivoted its efforts toward developing an “Indelible Ink” — a mark signifying citizen participation in the electoral process and preventing attempts at double voting.
Years of research and experimentation led to the breakthrough — a unique concoction based on silver nitrate. Upon contact with the skin and exposure to ultraviolet light, the indelible ink leaves an…read more on NOPR