As higher-end portrait photographers, we offer a lifetime guarantee on our prints so the inks need to be permanent. The genuine products for Epson, HP & Canon wide-format printers are just that. Our exterior signage was done on our wide-format and after 7 years, it's still as good as new whereas the earlier RA4 printed signs faded badly after just a few months.
This is one reason why I wouldn't use 3rd party inks for production.
The office printers are another matter and run with a CISS. The cost saving is huge and we just have to top up the 100ml bottles from time to time. The recently retired HP K5400 drank its way through 2 litres of ink!
