Writing implements deliver a fluid to a surface via compression to activate the ink cartridge.

The fountain pens are supplied with a convertible system for filling with either bottled ink or an ink cartridge.

As the pen moved along the paper, the ball rotated, picking up ink from the ink cartridge and leaving it on the paper.

They say we'll be banned from taking ink cartridges on planes from now on.

And it doesn't stop there - the school even mounts fundraising recycling collections (collecting anything from mobiles to ink cartridges).