Superior ink that is almost waterproof and therefore an artist's favorite. It's a good idea to write on more porous paper with this ink and let it dry for 24 hours before exposing it to water.
It's especially good to sign important contracts with this ink, because the paper turns yellow before the ink fades!
The ink bottle has a special reservoir for low ink levels. When the ink runs out, turn the bottle with the cap closed upside down and the reservoir will fill with ink and it will be easier to fill the pen with ink.