Bi-luminescent Security Ink

The CSIR and National Physical Laboratory have developed a bi-luminescent security ink and dispatched to the Bank Note Press in Dewas.

About the Ink

The bi-luminescent security ink glows in 2 colors- red and green when exposed to radiation of different wavelengths. When illuminated by a light source of 254nm, it glows red and when exposed to 365nm light, it glows green. The formulation is to be used for ensuring the authenticity of identity cards, government documents, passports, etc.


The ink was manufactured by mixing 2 colors in the ratio of 3:1 and heat treated for 3 hours at a temperature of 400 degree Celsius. The ink is produced as a white powder. It was then mixed with PVC. The color emission from the ink is due to 2 types of luminescence: phosphorescence (green) and fluorescence (red).


SPMCIL or Security Printing & Minting Corporation of India Ltd is a central public sector unit. It is categorised as a mini-ratna company and is wholly owned by the government. It is engaged in the production of currency notes, passports, visas, security paper, etc. The Bank Note Press in Dewas is one of its currency printing presses.


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