Why is color profile embedded

[lacerto]

(...)

[thomaso]

10 hours ago, Nirdesha said:

10 hours ago, thomaso said:

But in case a workflow insists to get a PDF without embedded profile that may cause issues or complaints.

Exactly my issue. I am printing this on KDP and they will ignore every embedded profile. I cannot send them a PDF with embedded profiles. So, if i send this file, it might print in a totally unexpected way, isn't it?

Rather no. Be aware that PDF / X always must contain the Output Indent info. This is just text and tells the receiving software which profile will result in correct colors. According to the PDF specs this profile may optionally / additionally be embedded. It is neither necessary nor does it any harm to the PDF, it's rather useless if it is a common, spread profile.

So, the receiving software can simply ignore these embedded profile data but it does not ignore the info about the profile (the Output Indent). In some cases where an embedded profile in an PDF / X causes issues these are related how the receiver (person or software) is 'preset' sotosay. It is not a failure to embed but one just might refuse if something occurs different than usual.

My personal reason not to like embedding common profiles is that they increase the PDF file size, especially the PSO... and ISO... icc files.

[Nirdesha]

21 hours ago, thomaso said:

Rather no. Be aware that PDF / X always must contain the Output Indent info. This is just text and tells the receiving software which profile will result in correct colors. According to the PDF specs this profile may optionally / additionally be embedded. It is neither necessary nor does it any harm to the PDF, it's rather useless if it is a common, spread profile.

So, the receiving software can simply ignore these embedded profile data but it does not ignore the info about the profile (the Output Indent). In some cases where an embedded profile in an PDF / X causes issues these are related how the receiver (person or software) is 'preset' sotosay. It is not a failure to embed but one just might refuse if something occurs different than usual.

My personal reason not to like embedding common profiles is that they increase the PDF file size, especially the PSO... and ISO... icc files.

But KDP say they ignore all information in profiles.

[thomaso]

22 minutes ago, Nirdesha said:

But KDP say they ignore all information in profiles.

They ignore profiles, and information in profiles (<– these are the embedded things, and a PDF can have more than 1 ! embedded).

But they don't say they would ignore the Output Intent. Since they recommend X-1a the even seem to prefer to get a PDF with Output Indent.
Again: The Output Indent is just a text info about a profile name, it's not a profile. And there is always only 1 Output Indent given with a PDF.

[Nirdesha]

42 minutes ago, thomaso said:

They ignore profiles, and information in profiles (<– these are the embedded things, and a PDF can have more than 1 ! embedded).

But they don't say they would ignore the Output Intent. Since they recommend X-1a the even seem to prefer to get a PDF with Output Indent.
Again: The Output Indent is just a text info about a profile name, it's not a profile. And there is always only 1 Output Indent given with a PDF.

Understood. So both of you guys recommend X-1a, yes?

[thomaso]

21 minutes ago, Nirdesha said:

So both of you guys recommend X-1a, yes?

Sorry, I did not follow all details of your dialog with Lagarto, so only for myself: Yes.

I also recommend to scroll through your exported PDF before upload to see if everything looks as expected.

(what me personally still a little confuses are the empty fields in your screenshot of the export setup for Space and Profile when you have X-4 selected. So I don't see what it would export. In another screenshot it seems that your document was created in RGB. Since you will export it as CMYK you should care more for the colors which might get changed by this conversion than worry about any 'perfect' X-version, in particular black text being K-only or 4-c. To me the printers info, posted by Lagarto, says quite clear that "PDF/X" is being "used" and "preferred", and also about its handling of transparency/flattening, which else might let X-4 appear useful as an alternative to X-1a, if there at all is any related content in your layout document.)

[Nirdesha]

4 minutes ago, thomaso said:

Sorry, I did not follow all details of your dialog with Lagarto, so only for myself: Yes.

I also recommend to scroll through your exported PDF before upload to see if everything looks as expected.

(what me personally still a little confuses are the empty fields in your screenshot of the export setup for Space and Profile when you have X-4 selected. So I don't see what it would export. In another screenshot it seems that your document was created in RGB. Since you will export it as CMYK you should care more for the colors which might get changed by this conversion than worry about any 'perfect' X-version, in particular black text being K-only or 4-c. To me the printers info, posted by Lagarto, says quite clear that "PDF/X" is being "used" and "preferred", and also about its handling of transparency/flattening, which else might let X-4 appear useful as an alternative to X-1a, if there at all is any related content in your layout document.)

Well, it shows empty by default but I can explicitly select CMYK and then it shows the profile as "document profile".

The 2 PDFs created either way seem identical.

On screen, X-1a seem pretty good. The colors are a little dull but I guess that is expected.

[thomaso]

Ok. Thanks for the info. Meanwhile I can reconstruct these empty fields: They appear empty if the documents color space is not CMYK (or grayscale with an according print profile) AND any of the PDF/X presets gets selected. Apparently in this case Affinity selects automatically this profile which you have set as default in your app Preferences > Color > CMYK... .

That means for now and your file: You could choose an export profile which is most common in the country where your PDF will get printed. E.g. for Europe, in particular Germany, the U.S. profiles are much less common than ISO... or PSO... profiles; in Asia other profiles are common than in Europe or in the Americas. (a reason e.g. is the different color taste in various societies, e.g. a warmer or cooler black printing ink.)

If you send your PDF for a profile which is not common there than your colors could become converted once more, into the local profile of that printer. That way the colors may change again a little, although we possibly won't see it unless we can compare two print results. However, there is no reason not to choose a profile according to the printer or its region. (Some printer tell a preferred or even deliver their custom profile, yours apparently does not).

Edit: And, of course, a profile according to the printing paper (as Lagarto mentioned already), since coated and uncoated papers "suck" the ink differently and therefore result in different visual intensity.