Multiple choice general knowledge history

What is name of the ink used for printing curreny notes?

  1. Optical Variable Ink

  2. Optical Versatile Ink

  3. Optical Volatile Ink

  4. Optical Virtual Ink

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Optical Variable Ink (OVI) is a specialized ink used for printing currency notes as an anti-counterfeiting measure. It appears to change color when viewed from different angles due to its special reflective properties. The other options (Versatile, Volatile, Virtual) are not real types of ink used in currency printing.