[pdftex] PDFX3 Standard

[Hans Hagen]

At 17:46 26/10/2003, you wrote:

>Is there a PDFX3 compatible TeX dialect, e.g. Context?

There are several standards and pseudo standards. In our country there is 
something called 'certified pdf' which is not really a standard but more 
some kind of agreement between pdf producers and users based in a 
commercial validation plug in.

PDfx on the other hand is a kind of open standard, or more precise: just 
pdf without a few things that rips can have problems with, so 'no 
transparencies', 'no rgb', 'fonts included'. There are several variation 
son pdfx, which has to do with the fact that printing houses in the north 
america, northern europe, southern europe and mid europe have their own 
preferences.

Concerning pdftex and context ... Pdftex by itself produces rather simple 
pdf, and this passed the pdf/x validation test rather well (there is a free 
plug in from callas which now is also part of acrobat 6 professional). The 
problem can be in

(1) embedded graphics [for instance, illustrator happily uses layers and 
transparencies fo rinternal purposes and therefore graphics done in 
illustrator explicitly need to be exported as pdf 1.3 (or less), or be 
flattened (by acrobat)).

(2) pdfliteral code; if i remember right, the main thing i had to check was 
that the color space should be cmyk [some of my debugging code used rgb so 
i had to adapt that a bit].

(3) fonts ... well, just include them and you're ok

There are a few additional pieces of pdf involved, for instance there need 
to be a cropbox and also an extra datestamp in the trailer (which is why 
the latest greatest pdftex can write info in the trailer).

To summarize:

- pdftex is pretty pdf/x safe
- graphics are out or our control so need special care
- the few left over missing bits and pieces are neglectable (and also a bit 
strange)

It is interesting to note that we occasionally get pdf files that are 
'validated and ok' but definitely not pdf/x. Also, you need to keep in mind 
that some graphics (read: illustrator graphics) when written in their 
native format (which is now pdf) contain some ps code (in some kind of 
comment object) as well as an (i presume) editable duplicate of the graphic 
(even preferences and strings can end up typeset in the file which means 
that in order to reuse them later the editing application has to parse the 
typeset code) that can confuse validators -- although it is supposed to be 
invisible to the viewing application (placed some 7000+ points in the 
margin and encapsulated in special objects.


Hans