CMYK and RGB

SamuelG

New Member
So Im just getting into graphic design after finishing my Concept Art degree, realised I wanted to go down a different path, so Im currently trying to learn everything I can whilst building my Logo portfolio. I want to understand CMYK and RGB fully as currently Ive been doing research and I am a bit confused about a few things. I know CMYK is for printing, and RGB is for web, I have read that I will need to provide the cleint with both, starting with CMYK then converting to RGB, this all makes sense, but iw what I cant seem to understand is CMYK looks very dull and lifeless, but I have to keep those same colours when I go over to RGB right, because the point is to have a cohesive colour throughout your printed and digital media, but what if I want the web version of the logo to be brighter because otherwise it looks too dull, is it out of the question to have the web version a brighter more saturated colour, hence the printed media and web based media versions looking quite a different colour? Ive been looking at lots of different logos and Im sure most of the ones on I see online are using colours that wouldnt be possible in CMYK, yet obviously they have printed versions, I hope my question makes sense and I hope someone can help me out. My logo just looks so much better in RGB as I think most logos do.
Thanks
 

Levi

Moderator
Staff member
If a logo is done correctly it will look near identical (there's always going to be a slight variation between medium) on a screen as it would being printed.

Obvious things to consider are colour profiles and calibration but you also need to consider screen and/or paper being used etc.

Honestly if your cmyk colours are dull it sounds like you need to calibrate and/or use brighter colours (might need to tweak a setting that I can't remember name of in illustrator for rich blacks too)
 

hankscorpio

Moderator
Staff member
CMYK will be ok - but depends on what colour profile you are working with. The colour profile is dependent on output, for example you can have US Web Coated SWOP.
That's clearly marked for the US market - web specifies the Web Press (it's printed off rolls of paper instead of sheets (sheetfed) - and as it's Web press and geared towards faster print runs (like newspapers) and the paper is quite pourous - the ink limit is set to 300%.

300% ink limit literally means that when your mix of colours in C M Y K = 300% that's the limit your paper can take (like wetting a paper bag, eventually it will just tear if it's wet enough - right?)
If your logo is made of 90% cyan - 60% magenta - 80% yellow - it equals - 230% for ink it will work.
If that colour has a 75 % black - then it will be 5% over the ink limit.

There's plenty of CMYK profiles - for different printing standards - like Euroscale Coated and Euroscale Uncoated.
Coated and Uncoated refer to the paper type - if the paper is coated (like magazines) or uncoated (like newspapers).


This is why designing something in CMYK is not ideal. Converting between colour profiles causes colour shifts - as the ink levels can increase/decrease - for example sending a logo with 350% in coverage to be printed at a newspaper would end up the colour being adjust on output - so that there isn't 350% ink coverage but only 300%.
Do this they need to reduce the C M Y K coverage in the file - reducing the CMYK numbers changes the colour output.


That's a very broad coverage of it.

What you really need is a colour book - like Pantones Coated and Uncoated books.
In Japan (and parts of Asia) they use TOYO - a different set of colour books and don't use Pantone.

This doesn't mean you need to design in Pantone and TOYO - it's just to be aware that different parts of the world use different standards.


Anyway - when you use Pantone colours - you buy the Pantone books - and you pick from the Coated or Uncoated sets.

You very rarely find a colour in the Coated book that matches the same colour in the Uncoated book.
That's because the ink colour shifts when applied to different papers, on uncoated stock (like newspapers) it saturates more (like a wet paper bag) the ink becomes duller.



When you use Pantone Colours - you can define your spot colours as LAB colour system in Illustrator now.
L*a*b* L* for perceptual lightness, a* and b* for the four colours of human vision: red, green, blue, and yellow.
Because Lab describes how a color looks rather than how much of a particular colorant is needed for a device (such as a monitor, desktop printer, or digital camera) to produce colors, Lab is considered to be a device-independent color model.

Do you need to get bogged down in this?
No.


Pick up a pantone set of books - coated and uncoated.
Pick from them.

It will also show you the CMYK equivalent beside it - again - this is rarely the same shade - because the CMYk equivalent can't be produced.
It's often best to pick a CMYK equivalent from another swatch in the book.

You can see here in the pantone book - that the SOLID (spot) is nowhere near the CMYK equivalent.
For this I'd pick a different CMYK from the Pantone book that would be closer to the original.
You can see it gives the RGB and Hex Colours too.

1613413664513.png
 

eddypeck

Member
Worth bearing in mind the basic difference between reflected and projected light.

CMYK ink on paper is reflected, you see the colour based on the amount of Cyan, Magenta, Yellow and Black laid on the page, with the light shining on it and reflecting back into you eye.
RGB colours on a screen are projected, based on the brightness of Red, Green and Blue pixels of a screen.

When viewing CMYK colours on a screen, you're seeing the representation of these converted to light as the RGB of the screen.

Back when I started out I remember the studio I worked for spent a fortune on high end screens and had some device that would clip onto the screen to calibrate them. When that was done we had printed panels to hold next to the screen and colour match the best we could for that final human tweak. 99.9% of what I do these days is web based so it rarley matters but when I do have to do a full branding job it's nice to get back to my print roots.

The other thing to consider is printing out on your inkjet or laser printer will again be totally different that the results off a printing press.

And the final thing to think of, once you've got your head around this... in the commercial world you'll be forever trying to explain it to clients. When you get their business cards printed and hold it up against their website on their cheap ass uncalibrated monitor and say the colour of their logo is wrong. I generally tell them to go look at it on someone else's computer and they'll see it's still wrong, but in a different way :giggle:
 

hankscorpio

Moderator
Staff member
And the final thing to think of, once you've got your head around this... in the commercial world you'll be forever trying to explain it to clients. When you get their business cards printed and hold it up against their website on their cheap ass uncalibrated monitor and say the colour of their logo is wrong. I generally tell them to go look at it on someone else's computer and they'll see it's still wrong, but in a different way :giggle:
This!

Whatever you do - if you're getting stationery sets printed (business cards/letterheads/compliment slips etc.) get them all done in the same printers.

I had a guy get his business cards printed in one place, and another place did his letterheads and compliment slips for cheaper...
The colours didn't match, one was printed on a digital printer - the other on a litho press using spot colours.

Morale of the story - always send a printed sample or a colour reference (like pantone colour) the printer for reference.

Otherwise. It can be anything!
 

Levi

Moderator
Staff member
This!

Whatever you do - if you're getting stationery sets printed (business cards/letterheads/compliment slips etc.) get them all done in the same printers.

I had a guy get his business cards printed in one place, and another place did his letterheads and compliment slips for cheaper...
The colours didn't match, one was printed on a digital printer - the other on a litho press using spot colours.

Morale of the story - always send a printed sample or a colour reference (like pantone colour) the printer for reference.

Otherwise. It can be anything!
And include in your t&c's etc about colour varying between screen/printer/inks etc and how they can be different just in case they want to be 'annoying'....
 

Simon Lewington

New Member
When you see a logo on screen there is light behind it. So its going to seem brighter than when its printed onto a media, which does not have light behind it. Hankscorpio explains it perfectly above but have a look at my article on Pantone colours
This may help understand the difference between CMYK and RGB a bit more.
 
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