This is kind of a dumb question, but I think I recall someone posting that cartridges might not work after the expiration date? I just can't recall if that comment was made in reference to Epson, Canon or HP?

Or none of those?

And it isn't an issue?

HP ink is a lot cheaper in the two pack. But the Z3100 appears to be so frugal with ink that there is a possibility that I'd be loading the second cartridge after the expiration date. Or it might expire while I'm using it. If that happens, would the cartridge keep working?

Thanks for any responses for a dumb question.

My understanding is that HP will not gauarantee the performance of the cartridge or the ink passed a certain date as their warranty documentation seems to indicate that it will work passed the expiry date.

That makes sense, and would be the same as ink for 4000. It continues to work past the expiration date.

But since all of these cartridges include electronic gadgets to read them, as well as the expiration dates, I decided to ask.

Better to ask a dumb question than to not know at all!

sure hope that "archival" ink works past the date!! : )

One thing to remember is that pigmens are particles and must be suspended in a liquid carrier. Many of us with LF printers are all too familiar with what can happen when carts sit for prolonged periods without agitation. The expiration dates, I would assume are related to the ability of the particles to remain in suspension.

In this regard, I spoke to Sr tech reps from both Canon and HP in recent weeks precisely about the issue of pigment settling. Both the IPF (canon) and Z (HP) series printers include maintenance routines that periodically agitate the inks in the carts. Both companies, and presumably Epson design their formulations to remain in suspension over a given period of time. I can't yet shake the habit of manually agitating carts every couple of weeks or so, so can't comment on how long before settling occurs in the new printers. But if it is indeed safe to wean myself from this preventative measure, that's an important advance that gets little press.