Why does my Canon inkjet printer require two black cartridges?

Question

I am curious why my Canon printer, an MG6320 (but I have also seen this on MG5320 and MG5220), requires me to use two black ink cartridges, one labeled BK and the other labeled PGBK. When I do a nozzle check, the one labeled BK prints a grid, while the one labeled PGBK prints a black rectangle. Which one is used for which purpose?

Solution

The PGBK (PaGe BlacK or PiGmented BlacK) ink does not adhere well to coated stock.

So that ink is used for regular printed documents.

In contrast, the BK cartridge holds dye-based black ink that is designed to last longer and retain its color longer when printed on coated photo paper.

So it is used for photos.

Source

Comments

[Bleeding Fingers]

You see. Just in case. ;)

[gparyani]

Yes, but why do some printers use a single black cartridge only? And why does the MG6320 specifically require a gray cartridge in addition to the two black ones?

[Daniel R Hicks]

@damryfbfnetsi - Could it possibly be that Canon makes more money selling the cartridges than they do selling the printers?? (Nah!!)

[gparyani]

@DanielRHicks That system can be easily gamed by refilling the cartridge with aftermarket ink. Canon printers somehow still recognize a Canon cartridge even filled with aftermarket ink as genuine cartridges. But it was possible to access Creative Park Premium even with non-genuine cartridges, by going to the direct link: cp.c-ij.com/cpp/en (that is, until Canon changed it)