I thought these tank printers used ink that was poor for archival purposes.
Not in such general terms - there are significant differences between companies and models and differences in the ink types - dye or pigment.
HP inks for their tank system printers perform very good, almost as good as Epson Claria ink, Canon dye inks for the G-series printers are of the fast-fade type, and you need to differentiate Epson models by type - the lower end L3xx series and ET2xxx and ET3xxx are as well pretty fast fading inks, the inks for the ET7700/7750 are identical with the Claria inks and the inks for the L805/850 and L1800 are in between - better than the inks for the ET2700 but not as good as the inks for the ET7700. But there is no problem to use the ET7700/106 inks in the L805/1800 , that's what I do.
There is regrettably no detailed information anywhere in the Epson/Canon marketing documents other than statements that prints may last for gernerations to come - in an album.
So you are basically on your own when it comes to these criteria. And Epson now is offering as well Ecotank Printers with pigment inks like the Durabrite inks for office type applications.
Warranty conditions are set by the manufacturer and vary by country, they may create a threshold beyond which they assume commercial use, and warranty for commercially used equipment is different anyway. you find such usage limits in lots of product specs, sometimes very much hidden in the fineprint. I was and I'm doing much more than those numbers
without problems.
