Colorverse Office Series Permanent Black 30 mL bottled fountain pen ink. 
The Colorverse Office Series features ten staple fountain pen ink colors (including three permanent inks) designed for everyday use in (or out) of the office, in 30 mL glass bottles.
Made in Korea.
 
This ink has been designed for use in fountain pens and is perfectly safe, however due to the waterproof and permanent nature of the ink, it can be difficult to remove from pens if allowed to dry out in the pen. It may also permanently stain some types of plastic pens, particularly transparent demonstrator  pens. We recommend regular use of any fountain pen loaded with permanent ink as well as practicing good pen hygiene (regular flushing).