If you ever looked really closely at an image in the newspaper, You’ll notice that the’re
made up of tiny little dots.
Look a little closer, and you’ll notice that there’s only 4 colors of dots: Cyan,
Magenta, Yellow and Black.
Hypothetically, If you were to do this to your TV or computer screen, You’ll find
somewhat similar happening.
Instead of dots, you’ll find pixels, and instead of the four colors mentioned before,
you’ll find three: Red, Green and Blue.
These are the two color models RGB and CMYK.
What’s the difference between these two model and why do we need both of them?
RGB stands for Red, Green, and Blue while CMYK stands for Cyan, Magenta, Yellow and
Key, which is essentially Black.
If you use Photoshop, you might’ve noticed that you can edit between the two color models,
and you might’ve even noticed that they’re on opposite ends of the spectrum when you
color balance your photos.
Both models will even provide a similar color range.
But the reason you need both of them, is because they’re good at different things.
RGB is an additive color model that mixes the three primary hues to create an array
of different colors.
Today, it’s mostly used for electronics and computers, but it stems from an earlier
understanding of Trichromacy.
The first color photos in facts were created by taking 3 black and white photo of the same
thing, but each with a different color filter of Red, Violet-Blue and Green.
When you superimpose the three different films, You get a colored photo.
RGB creates color by superimposing colored light on a black surface.
The more light used, the brighter the color, and the dimmer the light, the darker the color.
If you combine the full color of the full light of all three hues and you get white
light.
CMYK, on the other hand, is a subtractive model.
It is often used for dyes and printing.
Unlike the light of RGB, we perceive CMYK according to the certain wavelengths that
are absorbed.
Those not absorbed are what remains visible.
CMYK can be a little more intuitive.
The less color applied, the lighter it is, and the more color you mix, the darker the
color.
And Black?
The letter K stands for “Key,” a term that is a vestige of printing presses, when
you have to “key up” or align your plate..
There are multiple Benefits of using black, including the fact that
Cyan, magenta and yellow alone don’t actually create a rich black when mixed together.
It’s kind of more of a brownish color.
So you need a black ink to achieve a really dark color, and that is really important for
printing a photograph, because the darker the black the more contrast you have, and
that creates the illusion of a sharper image.
Second, it’s much easier to print a black and white file.
It would be really difficult to print a page of text with three colors.
If one of them were misaligned, you’d have random colors everywhere.
In addition, printing a large amount of color ink on a small area, can actually oversaturated
your paper, which can cause the ink to bleed and blur, that that’s especially not ideal
if you’re printing fine details, like type.
Lastly, color ink is expensive!
Black reduces the amount of color ink required, so it’s much more economical to use black
ink for really dark areas, or unsaturated colors.
So black is very practical, cheaper, and faster than CMY alone.
Wait..
Isn’t RGB supposed to be the primary colors that create all the other colors?
Why can’t RGB be a subtractive model?
Why can’t you print with RGB ink instead?
In some instances, RGB can have an upper hand.
As a general rule the more you mix physical pigments, the duller the colors will appear.
This is because pigments aren’t as pure as color light.
RGB can provide a more saturated color.
It even creates darker colors very well, but notice how it can’t create lighter colors
like yellow.
In the end, don’t expect it to kind exactly what you see on the screen.
So when should you use each color model?
If you’re making something that will be viewed on a screen, such as a website or video,
RGB is the way to go.
If you’re printing it out, most likely it will be in the CMYK format, unless your printer
specifies differently.
And remember how I said you could switch between the two?
Well it turns out that the conversion between RBG and CMYK is not perfect.
You’re going to have to go through a color management program, so there’s a lot of
room for error.
This might not make too much of a difference if you go from one to the other, but if you’re
making several passes between the two, you’re going to have a loss of accuracy.
If you just try to print a photograph that’s RGB format on a CMYK printer, the printer
is going to have trouble reading the format properly.
It’ll try to convert the color though its own color management program, which isn’t
as accurate as photoshop or illustrator.
Maybe that matters to you, maybe it doesn't.
It all depends on the nature of your project, and what you need from it.
What about scanning?
Scanners are often RGB, but if you’re going to print it, hold off on converting the file
until your open it in Photoshop or illustrator, They’re going to do a much better job of
converting the color.
Also, should convert the file before editing for color because you don’t want to convert
at the end, and notice you have to color balance and everything all over again.
And that’s the difference between CYMK and RGB!
I hope this is helpful.
Let me know if you have any questions or if I left anything out.
And I’ll see you guys next time, Bye!