Re-inking printer cartridges. Many sites exist that sell will-fits, refilled OEM cartridges or reloading kits. Some that sell bulk-inks have reference sheets as to what ink works in what printer...Not all inks are the same! My experience was reloading my own...can be messy, but every time I loaded a cartridge-set I saved $35-45 for maybe a buck worth of material.
Ink for 1 particular canon-cartridge, May not be suitable for all canon's