"harry" wrote in message
...
On Jul 18, 7:22 pm, Smitty Two wrote:
In article ,
"Ed Pawlowski" wrote:

"harry" wrote

You will not get black. That's why there's a separate black
cartridge.

It was not always like that. Check out an HP500C printer that had only
one
cartridge. It was not a true black, but "close enough" for most
people.

It's the difference between theory and practice. Nevertheless, the OP is
trying to forge black from what he has available. Equal proportions are
his best/only option and he gets what he gets.

No-one has been able to come up with the absolutely true RYB colour
pigments. That's why when you mix them you will only ever be able to
get a mucky brown at best. Nowhere near black.
It all stems from the subtractive and additive colour combinations.
Also what pigments can be manufactured.

That is why lithographic printing also uses four colors for color
photographs in newspapers, magazines and books. Years ago they tried three
color printing but the results were never good, and only used in some
newspapers because they didn't have the printing capability for 4 colors.
Coffee table books often use a 6 color process to enhance the color because
even the 4 color process cannot reproduce all colors accurately.