My old HP inkjet would keep working with the black cartridge as long as there was a color cartridge (even an empty one) mounted.

The problem started when that color cartridge went bad. I had to hunt for an old, used, empty color ink cartridge.

Oh, new color cartridges were available, but I didn’t want to cough up a tidy sum for it.

Now I’ve got an Epson inkjet. There are three color cartridges and one black one.

The trouble began when one of the color cartridges became empty. The darned printer stopped functioning.

Maybe I overlooked some setting for bypassing/ignoring the color cartridge.

PS

Holy cow, I've managed to squeak to 300 posts (and just before my b'day)

It varies from printer to printer, some will work with an empty cartridge some dont.

Regards

HP's are expensive because each cartridge has a printhead built in, effectively making it a new printer each time you change the ink. Most Epsons (i think) don't and probably just register as "hello, i'm empty, please replace me".

Engineering is used to sell lots of ink. Epson cartridges are NEVER empty. Cut one apart and you will see. Same with Lexmark, some Canon, and many HP printers built after 2005.
Energy Economics of Toronto published a study in which they showed that the average printer uses $223 of ink per year, or $1172 for the life of the average printer. Multiply that by the zillions of printers in use around the world, and you can see that ink is a money cow.
Dell is the worst. Lexmark is close since they make the dell printers.
Not all HP's have printheads in the ink cartridge. There are a large model of numbers that do not, but the price doesn't drop on the cartrige. The ones that have print heads have an additional huge cost with the print head wears out... Some HP's with separate print heads can cost $120 to $180 per year extra just for print heads.
Nearly all modern ink cartridges have sensors that "decide" when the printer ink cartridge is empty. Some count the pages, rather than volumetric flow.
Look at the capacity in ML of your ink cartridges of today, versus 1999 when the printing companies finally caught on.
What is more, printers are designed to wear out... where there is additional money to be made... Try buying printer parts from Brother, HP, Canon, Epson, where you will average $84 to $143 for a printer that may have cost less.

The profit comes from the ink, for sure.

But isn't it hand-twisting, to say the least, to force us to buy a cartridge.

All I wanted to do was to print out a few letters with the black ink, and had to wait till the next day for the shops to open.

Well you can always switch to a black only laser printer, where the cartridge will last much more than a year for the average user... cost per copy is extremely low. Just do not get a cheap printer... under $250. Samsung, HP, Konica Minolta, Fujica, Brother... all very good, but you better keep a backup ink module as they are not easy to buy at Wal-mart, Staples, or Best Buy.
There is no immediate help to any user for the problem you describe... except buy more carefully. The information is out there for people to ignore.

Then I did miss something.

Cost per page with an inkjet is around 10 cents per page. A laser printer will cost you 1-2 cents per page. Sure the printer is slightly more expensive but the toner will last much longer. I got a samsung ml-2010 from newegg - 100.00 rebate in end it cost me $50.00. The toner lasted over a year with heavy printing from the wife and kids. No color but who cares.

Okay, it's laser printer next time.