What do you fill your pen with?

Answer 1

A fountain pen can be filled by three means.

1) Via an ink cartridge which is simply pushed onto the feeder for the fountain pen.

2) Via a converter which is roughly the same as an ink cartridge except that it can be re-filled via a bottle of ink.

3) Via a dropper straight into the body of the pen as in the LAMY 2000 Fountain Pen

Answer 2

Ink!