Setting new TAC for FOGRA39?

[andyd34920055]

I'm new to photoshop but currently laying out a project to be printed.

The printer has specified I need to use the FORGRA39 color profile but keep the max ink levels below 280% for one set and below 250% for another set.

I know it's possible to make a custom profile and cap the TAC but I need to make sure everything else complies with FOGRA39 for the printing. Is it possible to convert my RGB files to CMYK FOGRA39 and alter the TAC to keep everything below 280% in that profile?

Thank you so much for any help.

[Stephen Marsh · Accepted solution]

@andyd34920055 – You are correct that the legacy Custom CMYK will not conform to Fogra39.

You can convert a copy to a profile that gives you a lower TAC, then layer this over your Fogra39 image and change blend mode to luminosity, with blend if sliders or luminosity mask to restrict the blend to the shadows... But this is a little clunky.

Using selective color and other methods to reduce a higher TAC to a lower one often creates weird transitions in darker tones.

So the best option is to use a proper F39/ISO Coated v2 ICC profile that has been created with a lower TAC:

https://shared-assets.adobe.com/link/f3918e2e-1db4-4ecc-6ffc-720d8f5dfa08

Due to the very large file size of these profiles, I would recommend that you assign the Adobe or another smaller F39 profile to the image after conversion so that the final saved file size isn't bloated by the VIGC Max TAC profile.

[andyd34920055]

This is incredibly helpful, thank you! 

Just to clarify since I'm a bit of a novice here, these ISO profiles are set to the data sets of FOGRA39? If you, you are an absolute life saver. I've been searching the net for quite some time and was coming up empty handed at every turn.

[Stephen Marsh]

This is incredibly helpful, thank you! 

Just to clarify since I'm a bit of a novice here, these ISO profiles are set to the data sets of FOGRA39? If you, you are an absolute life saver. I've been searching the net for quite some time and was coming up empty handed at every turn.

By @andyd34920055

ISO Coated v2 uses the Fogra39 characterisation data.

Also keep in mind that depending on the profile, the rendering intent can provide very different TAC for the same profile.

If you convert to profile using a VIGC Max TAC ISO Coated v2 profile, then assign a F39 profile, there should be little to no visual change in the image (obviously shadows may be slightly lower in density to the lesser total ink). The whole idea of these profiles is that the VIGC performed exhaustive real-world press testing to come up with a set of profiles using lower TAC which produced the same/similar appearing density as profiles using a higher TAC.

I don't know why the VIGC took down the profiles, but I was lucky to get a copy of them before they did so.

[andyd34920055]

I really can't thank you enough. 

[Stephen Marsh]

I really can't thank you enough. 

By @andyd34920055

You're welcome!

[andyd34920055]

I actually have one more question you may be able to offer some insight on. Apologies for my lack of knowledge on this.

Once I've converted my image to the ISO Coated v2, if I tweak the color a bit using mode>curves, will any adjustments I make there keep everything eithin the parameters built in to the color profile I've converted to? 

Just want to make sure I'm not undoing anything by making those adjustments. Thank you again.

[Stephen Marsh]

Editing in CMYK will change the values, which may or may not be a concern. Certain edits that you make have the potential to affect total ink limits or to change grey balance etc.

Unless you know what you are doing, it is best to work in RGB and convert to CMYK at the end. Even if you do know what you are doing, some edits are just easier or only available in RGB (i.e. certain filters).

[NB, colourmanagement]

@Stephen Marsh "

Editing in CMYK will change the values, which may or may not be a concern. Certain edits that you make have the potential to affect total ink limits or to change grey balance etc.

Unless you know what you are doing, it is best to work in RGB and convert to CMYK at the end."

totally agree with that Stephen, and I've saved those profles too, useful - I'm so pleased you posted them

neil barstow, colourmanagement net - adobe forum volunteer - co-author: 'getting colour right'
google me "neil barstow colourmanagement" for lots of free articles on colour management

[Stephen Marsh]

While on this topic, a F39 profile using a very strong GCR can be found here:

https://www.colormanagement.org/en/isoprofile.html#coated_FOGRA39_GCR_bas

https://community.adobe.com/t5/photoshop-ecosystem-discussions/apply-ucr-gcr/m-p/11789237