Not so with pigmented inks. Pigmented inks are used in most black inkjet cartridges today. Epson has a version of color pigmented inks they call DuraBrite inks. They are very expensive to make and there is quite a hefty premium on bulk inks from any manufacturer that I have contacted.

DO NOT use pigmented inks in any cartridge that was designed to use dye based ink.

Generally speaking, HP and Lexmark inks are interchangeable because their process' are similar. Watch for color variations though.

The newer Canon cartridges, BCI-3e and BCI-6 colors are so close that I cannot tell them apart. Ironically cartridges are physically identical except for BCI-3e black which is slightly larger. The BCI-3e black takes pigmented while BCI-6 takes dye based. Be careful here. Some of new Canon printers take both BCI-3e and BCI-6 black cartridges. A lot of people are scratching their heads over this one. Now you know why. You get best of both worlds. Pigmented for archieval and dye based for photos. Since color inks are dye based and pigmented inks do not mix well with dye based inks.

To wrap it up I'll say that you can use most inks in most printers with exceptions that I already mentioned. Color variations, if they occur, might be compensated for in printer driver settings. Be prepared to fiddle with it. Physical damage to printer is unlikely in any case, unless cartridge is leaking when you put it into your printer. But you wouldn't do that. Would you?

Another alternative is to take printer with you and use buttons on front panel to manually do a cleaning every so often.

If you can locate some cleaning cartridges on net, just install them and run a few head cleanings, leave cleaning cartridges in printer then turn it off and enjoy your trip. The cleaning fluid will keep your print heads moist and ready to print when you get back. Tape up your ink cartridges and store them in an upright position, i.e., normal position they would be in if they were in your printer.

While Roy's 3 month leave is probably exception rather than norm it still raises question of what to do in his situation. He decided to do nothing and hope for best which was probably best choice.