Everyone has seen these, the dreaded ink refills that make using ink printers affordable. They are a mess to use, and what's worse than ink--stained fingers is that it doesn't always work. Sometimes the cartridge goes bad.
Most of the time, these things have sponges in them that eventually harden-- at which point they become unusable. The other problem is that if you don't use the printer all that much, the print head clogs or corrodes.
I had, like most, discovered by accident the secret to getting an ink cartridge to last for almost a decade. When my printer finally died this year, it still had the original cartridges that had gone through thousands of pages over the last 19 years, just by following these simple (but annoying) rules.
Rule 1. Once a month, print a test page and tell it to clean the heads. This costs very little ink and wastes one page of paper, but it keeps the heads in good working order.
Rule 2. Refill after every printing of more that 5 pages. This makes sure the sponges remain full and wet. Wet, they don't get hard. But even unused, they dry up from evaporation... so topping off the tanks on a regular basis (every few months even if you don't use the printer at all) instead of waiting for them to go empty before refilling keeps the sponges in their best shape.
Rule 3. Some printers now count pages and use fancy sensor chips to defeat the rules and force it to stop working after printing an 'impossible' number of pages. If you get one of these, it might be time for a new brand of printer or a 'reset' trick (the internet is full of them) or, if you love the printer, you might find a reset device online.
Laser printers (if you can afford them) have none of these problems, but it's hard to find a color laser for $30, you can find ink printers for $30 just about everywhere you look.