What ink used to make Indian currency note?

Indian currency notes are primarily printed using a special ink that contains a combination of water-based and solvent-based components. The ink includes security features such as color-shifting pigments and fluorescent elements to prevent counterfeiting. Additionally, the Reserve Bank of India employs a range of ink colors for different denominations to enhance visual differentiation and security. The specific formulations are closely guarded to maintain the integrity of the currency.