Colour Consistency

Mal Kol

New Member
Dear Members,

I have been a graphic designer for around 15 years now but have never found a proper workable solution for colour consistency across web and print using all the systems that have been put in place to address the problem, namely: Pantone colour libraries and bridge swatches that give values for coated/ uncoated stocks, Adobe Creative Suites preset colour profiles such as FOGRA39 and monitor colour calibration using devices such as XRite's i1 Display.

I suppose the reason why i am posting this thread, is because with all these tools at my disposal i am still getting colour inaccuracies 15 years on. I know colour is a problematic animal and you can never get 100% accurate results but after all my care and expense on the issue i am left wanting more.

I am based in London, UK, use Mac OSX and have created a custom profile for my Asus PG279 wide gamut monitor. I wonder what is the best workflow? Some users of this forums mention:

"Whereas, if your logo is in RGB then converting it to CMYK is easier as RGB has a wider gamut so your colours are more closely matched."

I always assumed the reverse is better, as if you were to make a logo in RGB you might use values that are not in the narrower CMYK gamut, and thus risk drastic colour shifts when converting... so limiting yourself to a narrower gamut from the outset would be sensible... no?

Also if i have my custom calibrated profile is representing colours on my monitor as accurately as possible... how does my printer know what the accurate colours im viewing on my screen look like to reproduce i wonder? What is the universal colour standard that devices such as the i1 adhere to. I know i can embed the profile in the artwork sent to my printers but i'm not sure if its used in print or simply for representation on screen?

I know there are hundreds of tutorials online and i have watched many, but none that i have found address how we should be using all these factors into one harmonious workflow.

Any help on this is much appreciated.
 
Another thing that confuses me...

I have two Pantone colour bridge swatch books: coated and uncoated. I understand the need to have different values for printing on different stocks, and when looking at the different swatch-types side by side they make sense; the uncoated stock looks slightly darker i presume because without coating (such as silk) the inks are absorbed more into the stock saturating the colour slightly, hence a deeper colour is required - please correct me if i'm wrong about this.

But then why, if the aim of pantone colour library is to produce accurate consistent colours, do the web/ RGB values for each of swtach-type coated/uncoated differ? Surely the web values should remain the same across both types as a screen cannot be coated/uncoated? Any clarification here appreciated.
 
A logo should be created in 1 colour first, usually black. Then colour added, no more than 3 colours, all spot colours using the Pantone colours.

The reason for Coated and Uncoated swatches is to show how the same ink looks on coated and uncoated papers. The same colour ink on coated paper looks lighter and on uncoated paper it looks darker.

The Pantone books come in handy - the designer then can choose the Pantone Colour that looks good on Coated paper - for example Pantone 186 (red) - you then go the Pantone Uncoated book and choose a Pantone colour red that is close to the Pantone Coated 186 - perhaps the closest colour to Pantone 186C in the uncoated book is Pantone 184U. And use the 184U swatch for the logo to be used on Uncoated papers.

This way you are choosing and creating a logo colours that are identical on Coated and Uncoated (or pretty close).


The Pantone books then have CMYK conversions. The conversions basically mean that it's the closest possible match.

CMYK and Pantone - these are different colour models. What you can generate in the Pantone model of colour cannot be created in CMYK - they are different colour gamuts. Therefore, the CMYK version will only ever match as close as possible to the Pantone.


When you convert the Pantone colour to RGB it will convert it as best as possible. However, when you go to print the file you may be undergoing another conversion to match the profile of the output device, or another profile. Then the RGB goes through the RIP and gets converted back to CMYK. It causes the logo to go through a double or sometimes even triple conversion.


Moral of the story - keep the Logo in the same colour model that you received it/created it.

RIPs/Printing devices (professional ones) have built in colour converters. If your logo is Pantone 186C and you're printing it through an RGB RIP - then the RIP will get the Pantone conversion from the Colour Look Up Table (CLU table) http://www.computerhope.com/jargon/c/clut.htm


That's not to say that if you're printing pantone 186C on uncoated paper that the CLU table will convert it to the nearest uncoated version. It will simply convert it to the nearest 186c in the CMYK or RGB gamut.


I highly recommend this course
https://www.lynda.com/Design-Color-tutorials/Color-Management-Fundamentals/135361-2.html
 
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