I ran across a GADGETWISE blog post that had some good insight about increasing the longevity of ink jet printer inks. I would say that the main takeaway of the article is that lack of use renders ink jet printers dead. That is something that I preach endlessly to my clients. By the way, this philosophy pertains to both small and large format printers.
It used to be that a print cartridge contained both an ink supply and a print head. But, many of the new ink jet printing systems incorporate more of a plumbing system. This allows the "ink tanks" to be a different component than the print head. There are definite advantages to this type of format, but in the end they are still suspect to the same type of failures.
Think of it this way. What do you do at your house when you have a hard freeze? You keep a faucet dripping, right? The same principle applies to ink jet printers. If the ink just sits stagnant in the lines, then there are potentials for things to get clogged.
So, the easiest fix is to simply just print! Anything! But, if you will be away for a prolonged period, the next best thing to do is to simply keep the printer powered on. Most ink jet printers have an internal "cycle" that will ensure that the fluid is flowing just enough to prevent a failure.
Read the original post from gadgetwise.blogs.nytimes.com:
This works for dye based ink but not for pigment inks. Many Epson, some Canon and some HP printers