Black ink doesn’t look as black to the human eye as black ink mixed with colours. There are some brands that will let you print black only, but the print quality will suffer.
The colour ink is also necessary so the printing dots unique identifying the printer can be printed on the page. Thanks to those dots the FBI can find exactly what printer was used to print a hostage letter (or any other kind of publication they don’t like). You can thank the American government for that one.
Black ink doesn’t look as black to the human eye as black ink mixed with colours. There are some brands that will let you print black only, but the print quality will suffer.
The colour ink is also necessary so the printing dots unique identifying the printer can be printed on the page. Thanks to those dots the FBI can find exactly what printer was used to print a hostage letter (or any other kind of publication they don’t like). You can thank the American government for that one.