> In theory, the combination of CMY at 100% (100,100,100) creates black, In practice it creates a muddy brown due to limitations of toner (and ink) secondaries.
Does anyone know why this is?
> "K" is used for black to avoid confusion with Blue and because the black component is the "Key" for a set of color separations
I always assumed it was just because "K" is the last letter in "black" — apparently not!
Because the subtractive primaries (CMY) in reality are imperfect, they cannot absorb 100% of the light that is shone upon them. This is also hampered by whatever substrate the inks are being applied to. (Tangentially this is why there is so much fuss over Vantablack.)
>I always assumed it was just because "K" is the last letter in "black" — apparently not!
Worth noting: the term "Key" goes beyond the colour black. It's referring to the keying colour, in some scenarios this would be the darkest of whichever colours are used in printing.
Depending on the printer you're using, the K in CMYK may also not be a typical black like what you would find in a black+white office printer, but rather something that you might consider a very dark grey. Subtractive colour reproduction is a bit of a rabbit hole, you can find printers that will include a variety of colours beyond CMYK in order to help fill out gaps in the CMYK gamut. Epson have a few printers like this, some which take inks in violet, green, orange, various shades of grey, lighter versions of cyan and magenta, florescent inks etc.
One reason is that printers inks do not have very dence pigment content. Pigment is the expensive part of paint/ink. Also, printers ink is very transparent, almost like a staining agent.
CMKY is basically a variant of the painter's RYB color space. A CMY mix using high quality painter's paints will get closer to black. However, generally mixing a black from primaries is waste of energy. Easier to mix from secondaries (e.g. an Alizarin Crimson with Ultramarine Blue).
> In theory, the combination of CMY at 100% (100,100,100) creates black, In practice it creates a muddy brown due to limitations of toner (and ink) secondaries.
i believe this may be because the combined absorption spectrum of a "full C M Y dot" still has gaps that a "full K" toner is engineered to cover?
With colored pigments (even ideal ones) white light would still need to bounce between all 3 to be absorbed. Some is going to bounce off 2 or 3 and come out colored.
[+] [-] gnicholas|1 year ago|reply
Does anyone know why this is?
> "K" is used for black to avoid confusion with Blue and because the black component is the "Key" for a set of color separations
I always assumed it was just because "K" is the last letter in "black" — apparently not!
[+] [-] quitit|1 year ago|reply
Because the subtractive primaries (CMY) in reality are imperfect, they cannot absorb 100% of the light that is shone upon them. This is also hampered by whatever substrate the inks are being applied to. (Tangentially this is why there is so much fuss over Vantablack.)
>I always assumed it was just because "K" is the last letter in "black" — apparently not!
Worth noting: the term "Key" goes beyond the colour black. It's referring to the keying colour, in some scenarios this would be the darkest of whichever colours are used in printing.
Depending on the printer you're using, the K in CMYK may also not be a typical black like what you would find in a black+white office printer, but rather something that you might consider a very dark grey. Subtractive colour reproduction is a bit of a rabbit hole, you can find printers that will include a variety of colours beyond CMYK in order to help fill out gaps in the CMYK gamut. Epson have a few printers like this, some which take inks in violet, green, orange, various shades of grey, lighter versions of cyan and magenta, florescent inks etc.
[+] [-] Daub|1 year ago|reply
CMKY is basically a variant of the painter's RYB color space. A CMY mix using high quality painter's paints will get closer to black. However, generally mixing a black from primaries is waste of energy. Easier to mix from secondaries (e.g. an Alizarin Crimson with Ultramarine Blue).
[+] [-] omgwtfusb|1 year ago|reply
i believe this may be because the combined absorption spectrum of a "full C M Y dot" still has gaps that a "full K" toner is engineered to cover?
[+] [-] itishappy|1 year ago|reply
[+] [-] Daub|1 year ago|reply
Actually, I think that this is a better reason.