I believe the 1320 (like a lot of HP and other printers these days) has a
'metering count' on the life of the ink cartridges.... so it doesn't matter
how much ink is left, when the meter runs out, the printer stops running.
I read a comment somewhere from a google inquiry that someone had
80% of their
ink left when the meter ran out and that was verified by an HP service tech.
I have never heard of this very interesting. I have serveral HP (
4000, 4200 an 4250) that I seem to get close to what they say you
should get on the number of pages out of them per cartidge. I got
that 1320 for one area here since it was a very low use area, will
have to check up on this now.