Printer Ink

There is no ink cartridge that can fit in every single printer ever made. People think they can go into a shop and say "I want a cartridge for my printer, it's an Epson." Aside from the fact Epson made dozens of printers that take dozens of different cartridge numbers of different dimensions, it's kind of hard what to say at this point. Going "You know what it is, you sold it me" doesn't really help the situation especially when you then mention you haven't been in for months on end and have only just noticed the shop's been painted (twice).

A printer that takes any cartridge you care to throw at it is anybody's ideal dream, just so they can go in a shop and say "I want some Epson ink". Which isn't as much fun as saying "I want some ink for my Epson, I don't know what the model is but I had some last time and they cost *some ludricious figure that probably wasn't right in the first place*"