The kind of thing that makes you say, Why didnt I think of this?

All Harry Potter Inks are packaged in a 50ml bottle featuring a cap engraved with the Hogwarts school shield. The first four inks correspond directly to the color-coding of the Harry Potter: House Colors collection, and are well known as the colors assigned to each Hogwarts house. The Knight Bus is a purple triple-decker bus that transports stranded members of the wizarding community, while Thestral refers to a sinister-looking breed of winged horse occasionally used for travel. Each color is labeled and boxed to match the packaging used for previous Harry Potter releases. This series of non-waterproof inks is free-flowing, non-staining and safe for use with all pen brands. Each offers medium lightfastness, without feathering and with reduced bleed

The kind of find thats worth adding to your collection.