ICC profiles and ink coverage

[SebastienV]

Hi 😉

I think I'm missing something with ICC profiles in Photoshop and I hope someone could light me up.

I'm need to send files to the print company that conform to Amber Graphic ICC profile. Profile is installed and I have assign it to my RGB picture. Up to now, everything is fine and my Total Ink Coverage is fine (less than 260%).

I want to make some color, hue, saturation corrections to my file. I'm using adjustment layers and flatten and save the file when I'm ok with the result.

But my corrections has change the ink coverage to more than the 260% authorised by the ICC profile.

• So, first question: is it logic that, with a specific ICC profile assign to my file, I'm able to modifying it up to going out of the profile specifications like Total Ink Coverage? (The analogy is maybe/surely false but for me it's a little bit like I would be able to use color in a grayscale mode image?!)
• Next question: Is there a way to re-assign the same ICC profile (try it but does nothing to my ink coverage) without switching to another random profile before re-assigning mine?

If I'm completely out of the correct path, please give everything you have 😄

Thanks

[c.pfaffenbichler]

»Profile is installed and I have assign it to my RGB picture«

One cannot assign a CMYK Profile to an RGB image and one generally should not assign an RGB Profile to an RGB image in another Color Space. 

There is a relevant difference between »Assign Profile« and »Convert to Profile«. 

» I'm using adjustment layers and flatten and save the file when I'm ok with the result.«

Why do you flatten? (And why do you do color correction in CMYK anyway instead of in RGB with soft proofing?) 

»with a specific ICC profile assign to my file, I'm able to modifying it up to going out of the profile specifications like Total Ink Coverage?«

If you work in CMYK then you can naturally violate the Color Space’s restrictions. That’s your choice, not some mysterious shortcoming of the Color Space. 

»Is there a way to re-assign the same ICC profile (try it but does nothing to my ink coverage) without switching to another random profile before re-assigning mine?«

Lab is a device independent Color Space and the Profile Connection Space, so converting to Lab and then to the intended CMYK space again would remove violations – but this is not a prudent workflow, especially when working in 8bit. 

»If I'm completely out of the correct path«

In general one should do the color correction in RGB (edit: for photographic images that is, for certain illustrations with black linework for example working in CMYK may be indicated), keep the layered RGB file and convert a copy to the correct CMYK space or convert on pdf creation from a layout application – that way the image cannot voilate the standard. 

[c.pfaffenbichler]

I edited the previous post to make clear that I was referring primarily to color correcting photographic images – just wanted to make sure this does not go unnoticed. 

With certain types of illustration or text-heavy designs working in CMYK may be indicated. (In the latter case Photoshop may not be the ideal application, though.) 

[NB, colourmanagement net]

Hi Sebastien,

For a start you DO NOT assign a profile to your RGB picture to make it ready for a printer, you must convert from your RGB colour space to the required colourspace as defined in the recommended profile [image/mode/convert to profile]. 

more here: https://www.colourmanagement.net/advice/about-icc-colour-profiles/

Is the Amber Graphic ICC profile actually a CMYK profile? I googled it and a paper manufacturer came up so I would think so.

However -  you mentioned you ASSIGNED it & you can't assign a CMYK profile to an RGB file.

[look at image/mode and check the mode -  CMYK or RGB]?

It's tough to answer your questions until we know more about this "Amber Graphic Profile".

I'll try some basic tips:

I will state that:-

The CMYK colour space does not constrain the contained image colour when editing after conversion.

The only time a profile constrains colour is during the conversion to CMYK.

Once an image IS CONVERTED to CMYK it's pretty easy to mess up and add saturation or density to the extent that the total ink limit (TAC) is violated.

And that potentially leads to big trouble printing.

So yes, the defined CMYK process has a max saturation and you can push your image outside that,

converting again doesn’t fix this, that’s a bad idea.

As you have seen assigning does nothing, don't do that.

For this reason a lot of very expert users recommend working on colour correction etc. in RGB and only converting [a flattened duplicate RGB file] to CMYK at the end of the colour correction process.

If you work on the RGB with view/proof setup/custom activated with the ACTUAL correct CMYK profile selected [maybe with gamut warning ON also] you can keep tabs on max saturation possible the destination CMYK colour space. 

Oh and working in layers then flattening, yes - definitely do that before you convert to CMYK. I'd make a copy of the RGB original, flatten that and then convert.

I hope this helps

if so, please "like" my reply and if you're OK now, please mark it as "correct", so that others who have similar issues can see the solution

thanks

neil barstow, colourmanagement.net :: adobe forum volunteer

[please do not use the reply button on a message in the thread, only use the one at the top of the page, to maintain chronological order]

[c.pfaffenbichler]

Indeed … 

Working in CMYK is a problematic choice and should only be undertaken after coreful consideration. 

Like I mentioned there can be cases where it is beneficial or even necessary but as we have no actual idea of the images in question this is academic.