Printer cartridge empty or not yet?

If my printer informs me that a cartridge is empty and waiting for a new one, I finish the printing process and let the printer stand for 3-4 hours. After that I can still print up to 30 pages with the "empty" cartridge.

deepblue25: Hello,

90% of current printers work with a (simply spoken) droplet counter. When the inkjet printer injects a dot of ink onto the paper, one unit of a predetermined number is withdrawn in an internal counter. It does not matter if the printer releases a small or large ink splash.
Now, for example, the manufacturer specified that a maximum of one cartridge 1,000,000 color dots can be set after this number is over and the printer reports that the cartridge is empty. No matter if there is still a sip or not.
There are the so-called "chip resetter" which reset the counter chip on the cartridge, so the counter back to zero. This is often needed to refill cartridges. But that has a little catch. Because once the cartridge is not filled with enough ink and the print head runs empty, the entire print head can break because the ink also works as a coolant. It does not have to happen right away, but sooner or later you will not like a printer.
However, there are manufacturers in which at the same time with the cartridge and the printhead replaced. Since then a defective part is repaired quickly. For many models, however, this head is firmly installed and a repair would significantly exceed the original price of the printer. This also means electronic waste and waste of materials.

For info: You can see on the cartridges if a printhead is installed in the cartridge. If there is an opening when replacing the cartridge when inserting it (hole that was originally covered with a thin film), there is NO printhead installed. (Epson, Brother, Canon, ect.) There in your own interest, the cartridge NEVER completely empty, whether refilled or original part.
If there is a gold or silver colored area on the bottom of the cartridge, with a micro nozzle attached in a narrow row, the print head is integrated into the cartridge. (HP, Lexmark, ...) There as well as possible, do not let the cartridge run empty so as not to damage it, but the exchange is made easy and fast.

I hope to have informed, and no I do not stand on a payroll from a printer manufacturer. I've just learned in a painful way how not to handle expensive cartridges ... strolcher: I ignore the message that my printer needs a new cartridge, basically. I know then that I'll have to get a new one in the future if I do not have any more at home, but I just leave the message and print until I realize that it really does not print properly anymore.
These messages are always far too early.
The stand with the 3-4 hours I do not understand. I just click the message away and then he prints again. But maybe different from printer to printer?