Canon BJC-250 - Manual (Page 59)

BJ Cartridge Maintenance
The most important thing you can do to extend the life of your printer and to ensure
optimum print quality is to take care of the BJ cartridges.
Spilled ink can stain any surface. Open BJ cartridges carefully, and follow the guidelines
presented here to protect against spilled ink.
If you are using the BC-05 Color BJ Cartridge and any of the other BJ cartridges,
make sure you store the cartridge not being used in the Ink Cartridge Storage Box.
Keep BJ cartridges in their sealed containers until you are ready to use them.
If spilled, the ink is difficult to remove. Therefore, it's a good idea to keep the BJ
cartridge out of reach of children.
Do not touch the print head area on the BJ cartridge. Ink may leak out and cause
stains.