220 ink cartridge empties before 221

[hyepriestess]

re MX870:  the 220 ink cartridge is used up before the 221.  i have several extra 221 black cartidges from the "color pack" purchases, but have to keep buying the 220...  something's wrong with this.  what can i do?

[Michael]

Hello.

The 220 Black tank is used when printing standard text documents on plain paper.  The 221 dye based black tank is only used when printing on photo paper.  

If additional assistance is needed with the ink tanks, find more help at Contact Us.

[hyepriestess]

how does the machine know what kind of paper i'm printing on?