Do you own an HP printer?

[InbetweenDreams]

One little tip is never change the cartridges even when your computer advises you that the ink is low. Leave it until the actual printer refuses to pring. That is when the ink cartidge is empty. When it is "low" it will go on printing for quite a few pages.

Oh yeah, I wait until it refuses to print and HP is well pretty forceful about that. I don't replace the cartridges until they are empty...

I also think that you should either refrain from power cycling the printer often, as it goes through it's start up routine the printer will end up wasting ink on each power up...