Re: Orthodoxy of standards, Is it really wrong to ignore profiles allways?
> {quote:title=Lukas Engqvit wrote:}{quote}
> Does Adobe expect people to understand that?
Of course. As we're also selling shares of a bridge over the San Francisco Bay for anyone that wants
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Seriously, as many here and other forums have commented - it's hard enough to get everyone to use PDF/X itself let alone use it correctly. But that's also why we try to enable our software (CS, Acrobat, APPE, etc.) to "do the right thing" as much as it can, so that user's don't need to worry. For example, Acrobat 9's printing system is now PDF/X aware and, by default, will do the rights things with your colors. It also knows about APPE and can send the files directly there w/o any changes!
>As far as I know Adobe ships Creative suite with Europe Prepress Defaults with FOGRA 27 profile as the default. Consequently every home made designer creating print ready PDF's will create PDF's with FOGRA 27.
>
Since FOGRA 27 was the standard at the time we shipped CS3 - I wouldn't expect otherwise _IF_ the user has chosen Europe Prepress. However, since we ship with US Prepress default (aka SWOP) as the defaults, I am sure there are MANY MANY more documents with SWOP as the Output Intent.
> Strictly speaking then all offset printers must then honour the ICC profile FOGRA 27, and if they wish to implement the current standard which is FOGRA 39. Ergo every job must be CMYK to CMYK converted to conform to going standards. Or is Adobe expecting everyone to print to FOGRA 27 (which is not possible).
>
Let's rephrase this a bit...
When printing a PDF/X-4 document with an embedded FOGRA27 profile to a device that is calibrated for FOGRA 39, then Acrobat (or the RIP) will need to do a CMYK->CMYK transformation of any DeviceCMYK data contained in the document as part of the printing process. Since the user proofed their colors with FOGRA27, donig so is the only way that the colors in the PDF can match on plate. "Swapping profiles" will NOT do so - since there are differences in various color values between the two profiles (or they wouldn't have bothered to update, now would they
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> Can I define that my press is both FOGRA 27 and FOGRA 39 and ISO Coated v2 (ECI)?
> Is this sensible? Is that what the rules intended?
>
If your press is capable to being calibrated to multiple profiles - great!
> This means that the PDFx standards encourage CMYK to CMYK conversion, this is contray to what I have heard from the Adobe Partner Seminars, where I have been told that Adobe discourages CMYK to CMYK conversion.
>
I can't comment on what you heard or from whom...I can only tell you what the standard says. And, of course, you are welcome to purchase a copy of the spec for yourself and read it as well.
> If I create a transparent Device Link profile, I am not violating the rules?
>
NOT at all! The details of how one does the "CMYK->CMYK transform" is left as an implementation detail in the spec, though covered in a separate "informative" document called the Application Notes. In there, DeviceLink is certainly one (recommended) method.
> If I choose to override a profile conversion, because I know that the characteristics are the same as the charectistics described in the profile (winthin standard deviation) – then I am violating the PDF standard?
>
PDF/X Standard, yes. (and be aware that YOUR definition of StdDev and your customer's may vary)
> – In profile conversions, as any colour maths there is a risk for banding.
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Banding in a profile conversion? How so?
>Adding a rule forcing CMYK to CMYK conversions on homogenous profiles
>
Actually, PDF/X-4 very clearly states that equal profiles are NOT allowed - so as to avoid this problem. But FOGRA27 and FOGRA39 are NOT equal profiles - they differ, and thus must be converted between the two.
Leonard
