The K in CMYK is grey, not black. The other ink tones are added to make it appear black.
Edit: It seems people don’t want to hear that. But sorry, that’s how CMYK works. Black is roughly C=75 M=68 Y=67 K=89 in most major colour profiles used for printing. When you tell your printer to print something black, it won’t use just Key (around 85-90% grey), and will apply normal CMYK blacks which use value from all 4 inks.
It’s been like this for 120 years and is not a “big printer” conspiracy. If you don’t like this, don’t use a CMYK printer. It’s just going to print CMYK values with CMYK inks like you told it to and none of those inks is black.
My color laser printer uses only K to print blacK. It takes four cartridges, and I’ve only had to replace the C, M, and Y cartridges once in the 15 years or so I’ve owned it, because I almost never print pages with color.
It sounds like your printer has a true monochrome mode you can specify. Makes and models that are more user-hostile often use drivers that default to grayscale for non-color prints.
That’s not really the case (grey), but it’s what happens by default.
The K does stand for blacK. The four are mixed to create a richer black than the black alone would provide - which conveniently looks better and uses more ink.
The software and printer are more than capable of not using “rich black” outside of images, but even the solid black ink will look muted to people used to seeing the mud from all four colours in their 12 point Times New Roman.
A sad state really that in 2024 we still have an ink racket.
