Out of Gamut query + 100% black text

[Chris26]

Hallo, This is a twofold question:  The first concerns the Two attachments:

1. The BEFORE attachment shows the image before FOGRA39 proof.  The AFTER attachment shows with 'Out of Gamut' selected.  Question:  Does this mean that the black (which are the dark shadows) will print lighter or darker when sent for printing? I never ever had this issue before with shadows.

 

2. How do I know if my text is 100% black or has been mixed with CMYK?  I only ask because this image has normal text on the image.  I am told to send text as 100% black, BUT the file must be converted to CMYK???  Never ever done this before, all files have been submitted as RGB to printers.  But this printer requests the file be converted to CMYK.  I must admit to being both lost and ignorant on this one, what happens then to the text?

[walt.farrell]

1 hour ago, Chris26 said:

Question:  Does this mean that the black (which are the dark shadows) will print lighter or darker when sent for printing? I never ever had this issue before with shadows.

It means it will probably print differently. Off-hand I'm not sure if it would be consistently lighter or darker.

1 hour ago, Chris26 said:

How do I know if my text is 100% black or has been mixed with CMYK? 

If you're changing the document color profile, the text color will change, and even if it started out at 100K in your document, it will be some mixture in the output file.

[thomaso]

4 hours ago, walt.farrell said:

6 hours ago, Chris26 said:

How do I know if my text is 100% black or has been mixed with CMYK? 

If you're changing the document color profile, the text color will change, and even if it started out at 100K in your document, it will be some mixture in the output file.

If you need to export in a different profile than your layout document you can maintain swatch values by switching the document profile before export with the option "Assign" selected. Then in the export options keep the settings for space and profile at their default "… document …".

If you changed the profile with "Convert" and got text in rich black instead of 100 K you can use the Find and Replace panel to search for this specific text colour + replace it with 100 K. Or adjust the black in your saved text styles if you used those.

In an exported PDF you can check the text colour in the Colours panel by opening the PDF in Affinity and ensure it has the exported space + profile set and the lock in the Colours panel de-selected. If you exported as PDF/X then Affinity will recognize the correct space and profile anyway.

[NotMyFault]

9 hours ago, Chris26 said:

2. How do I know if my text is 100% black or has been mixed with CMYK?  I only ask because this image has normal text on the image.  I am told to send text as 100% black, BUT the file must be converted to CMYK???  Never ever done this before, all files have been submitted as RGB to printers.  But this printer requests the file be converted to CMYK.  I must admit to being both lost and ignorant on this one, what happens then to the text?

 

To see how colors get mixed, try color separation:

 

[Bryce]

If you have Acrobat you can view the separations and your ink percentages in your PDF before you send it. I recommend letting the printer do the color separations unless you know how the subtractive spectrum and printing work. Keep your "darks" in your picture to no more than 300% if printing offset.

[Chris26]

9 hours ago, walt.farrell said:

It means it will probably print differently. Off-hand I'm not sure if it would be consistently lighter or darker.

If you're changing the document color profile, the text color will change, and even if it started out at 100K in your document, it will be some mixture in the output file.

Thank you Walt.  I do not trust the Printer's information - I will send iy away as an RGB, after all this is the first time I have ever been asked to convert to CMYK, which makes no sense to me at all.

4 hours ago, thomaso said:

If you need to export in a different profile than your layout document you can maintain swatch values by switching the document profile before export with the option "Assign" selected. Then in the export options keep the settings for space and profile at their default "… document …".

If you changed the profile with "Convert" and got text in rich black instead of 100 K you can use the Find and Replace panel to search for this specific text colour + replace it with 100 K. Or adjust the black in your saved text styles if you used those.

In an exported PDF you can check the text colour in the Colours panel by opening the PDF in Affinity and ensure it has the exported space + profile set and the lock in the Colours panel de-selected. If you exported as PDF/X then Affinity will recognize the correct space and profile anyway.

Hi Thomaso, as I said to Walt, I will give all this a miss, -it really is making life overly complicated and I am not used to this.  The Printers machines should all be taking documents presented to them as RGB and the machines will always calculate the necessary changes to CMYK.  That is how it has always been, so why he requires things differently beats me - I have no time for this.

1 hour ago, NotMyFault said:

To see how colors get mixed, try color separation:

 

Thank you for your informative link, but it really goes over my head.  Too complex for me.  I understand colour management very well indeed, but this I will avoid.

1 hour ago, Bryce said:

If you have Acrobat you can view the separations and your ink percentages in your PDF before you send it. I recommend letting the printer do the color separations unless you know how the subtractive spectrum and printing work. Keep your "darks" in your picture to no more than 300% if printing offset.

Thank you Bryce.  Though once again I am being bombarded with stuff, I really do not understand this 300% black or what ever, in maths you can not have 300 % it is a mathematical impossibility.  😄  Having said that I am dealing with an RGB document being sent away to a printer, I have never in all my life had to understand manually messing with CMYK or Text not coing out as Black.......🤣

 

 

HOWEVER, perhaps some kind person could just explain this please, the help manual says the following:  What on earth is this?? Colour Profile and colour Space have always, always, been interchangeable concepts to me and I have never had problems with colour in documents.  I now find this?  They both say EXACTLY the same thing EXACTLY!  Phew...

• Colour Space—choose whether to use the document's current colour space or export using a selected colour space. Select from the pop-up menu.
• Profile—choose whether to use the document's current colour profile or export using a specific colour profile. Select from the pop-up menu.

[thomaso]

5 hours ago, Chris26 said:

They both say EXACTLY the same thing EXACTLY!  Phew...

• Colour Space—choose whether to use the document's current colour space or export using a selected colour space. Select from the pop-up menu.
• Profile—choose whether to use the document's current colour profile or export using a specific colour profile. Select from the pop-up menu.

We know already from various user feedback that the Affinity Help can be confusing or simply too unspecific – however, it is a Help only, not a Reference Manual which could have every aspect documented.

In your quoted part the help appears incomplete. It does not mention what "document's current colour profile" means in case you switched the colour space in the export option above (the colour space). It is the profile that was set in your app Preferences > Colour in the moment you created the document as new, empty file. You can check what "current colour profile" will be used if you switch in the export options an RGB document to CMYK by switching your document's colour setting from RGB to CMYK -> this will list a certain CMYK profile as selected in the menu. THIS is the one that will be used for export with the "use document profile" export option.

One reason for a print service to avoid colour conversion may be that they don't want to be responsible for those settings: A switch in colour space (RGB -> CMYK / or RGB -> Grayscale) can result quite unexpected, especially for adjustment layers and layer blend modes for instance (these may require quite different settings to maintain the visual impression in the other colour space). In my experience those print services often were using 'old' RIP software in their pre-press process while newer RIP versions would handle documents of newer PDF versions or layout applications more automatically correct.

[Oufti]

5 hours ago, Chris26 said:

Colour Profile and colour Space have always, always, been interchangeable concepts to me

We could distinguish:

Colour model is the general "language" in which colours are defined in an image. — https://affinity.help/publisher/English.lproj/pages/Clr/ClrModels.html

Pixels can be defined either:

• by only a bit each (solid black/white only) — FWIK, this is not available in Affinity.
• by a byte or two (gray scale/8 or grayscale/16) — which means that the range from 0% to 100% is represented by values between 0 and 255, or 16535. 
• by a byte, or two, for each of the three colour channels RGB
• by a byte for each of the four CMYK channels
• by two bytes for Lab colour space

 

Colour spaces are representations of all the different colours reproducible (gamut) in a certain colour model, for certain circumstances or devices. — https://affinity.help/publisher/English.lproj/pages/Clr/aboutClrSpaces.html 

You could compare it to a dictionnary…

They are specified in the Colour profiles (hence a common confusion. But sometimes, the term Colour space is also used in place of Colour model…)

 

Colour profiles specify which "flavour" (which accent, like Scottish or Australian, if we think about colour model as a language) of the colour model will be used and then ensure comprehension. — https://affinity.help/publisher/English.lproj/pages/Clr/ClrProfiles.html

They can be generic, standard or device specific.

They will match colours indicated in the document to an absolute reference colour space, according to their own colour space.

They are used to determine which exact value(s) (between 0–255) will be used to represent a specific colour in a certain colour space, corresponding to a specific technique (e.g. sheet offset printing with US inks on uncoated paper) or machine.

++++++++++++

5 hours ago, Chris26 said:

The Printers machines should all be taking documents presented to them as RGB and the machines will always calculate the necessary changes to CMYK.  That is how it has always been […]

Actually, not exactly. 

Last century, usual workflow was to require prepress operators to separate images in CMYK values, leaving them this responsibility. 

Since colour management systems were better understood, RGB workflow — up to the last export — has been increasingly common, but there are still old printers, old machines, and old habits! 

++++++++++

My practical advice

You coud certainly ask your printer to make himself the RGB-CMYK conversion (I agree with you it's a task to leave to professionals mastering it), but then you should offer him a special fee for this extra task. He will generally do it benevolently but will nonetheless appreciate your proposition… 

+++++++++

BTW, about the "mathematically impossible 300%"… I give you a full bag of cherries, a full bag of plums and a full bag of apples. You then have three full bags…   

If you have 75% of ink coverage for each of the CMY colours and 100% of black, you'll have 325% total ink coverage on the paper.

Adding blue and red inks under black is used to reinforce the darkest parts of an image: you'll get a richer black, with profound nuances. 

But this is not recommended for tiny elements, like text, for registration problems (misalignments between colours).

More than 300-330% (or about, depending on the paper, inks, etc.) of total ink coverage will not dry correctly and maculate.

Colour profile used when converting from the RGB colour space to CMYK can check and manage this. 

 

Edited July 27, 2023 by Oufti
Adding relevant Affinity help links

[Chris26]

10 hours ago, thomaso said:

 

In your quoted part the help appears incomplete. It does not mention what "document's current colour profile" means in case you switched the colour space in the export option above (the colour space). It is the profile that was set in your app Preferences > Colour in the moment you created the document as new, empty file. You can check what "current colour profile" will be used if you switch in the export options an RGB document to CMYK by switching your document's colour setting from RGB to CMYK -> this will list a certain CMYK profile as selected in the menu. THIS is the one that will be used for export with the "use document profile" export option.

 

Sorry Thomaso, this may be clear in your head as you wrote it, I know the dangers in that way of writing, but this is a jumbled mess in my head and I have tried to dissect your explanation without success.

Colour Space = ?? 

Colour Profile = ??

[Chris26]

9 hours ago, Oufti said:

BTW, about the "mathematically impossible 300%"… I give you a full bag of cherries, a full bag of plums and a full bag of apples. You then have three full bags…   

If you have 75% of ink coverage for each of the CMY colours and 100% of black, you'll have 325% total ink coverage on the paper.

Adding blue and red inks under black is used to reinforce the darkest parts of an image: you'll get a richer black, with profound nuances. 

But this is not recommended for tiny elements, like text, for registration problems (misalignments between colours).

 

Thank you for the explanation.  I sit corrected.

[PepGold]

12 hours ago, Chris26 said:

Thank you Bryce.  Though once again I am being bombarded with stuff, I really do not understand this 300% black or what ever, in maths you can not have 300 % it is a mathematical impossibility.  😄  Having said that I am dealing with an RGB document being sent away to a printer, I have never in all my life had to understand manually messing with CMYK or Text not coing out as Black.......🤣

 

Maybe this playlist could be helpful 

 

[Chris26]

5 hours ago, PepGold said:

Maybe this playlist could be helpful 

 

HalloPepgold.  I highly thank you for this.  I will go through the whole lot with great interest.  As a photographer I am well versed in colour management systems and Monitor calibrations.  But as a photographer I have never had to deal with CMYK directly since printers just take your PSD or TIFF files and print away and you get good results.  But I am now dealing with Printers and books etc, this is a whole new world.  Thank you once again.