RE: [XaraXtreme-dev] Printing on Linux

["Charles Moir" <CharlesM@xxxxxxxx>]

> > It's only PDF 1.5 that introduced transparency.
> 
> Actually PDF 1.4 (introduced with Acrobat 5).

Yep you're right John. PDF 1.3 was Acrobat 4, which was a subset of
Postscript 2, or was that 3.  What a nice easy numbering system they
have.

Xara Xtreme for Windows has nice PDF output (and is about the only way
we can get clean vector output with real vector graduated fills,
transparency and even vector transparency (via masking)). User can
select PDF 1.3 (in which case we flatten all transparency) or PDF 1.4
(in which case we don't) or soon to be PDF 1.5, 1.6 PDF-X (in numerous
variations).

Unfortunately this uses licensed third party PDF libraries and so is one
part we can't open source. This is partly why a Cairo filter that
supports vector grad fills and transparency as a way to create PDF and
SVG would be so good.

> Note that there is a new PDF/X standard in the making which 
> does allow transparency/blendmodes to be used.

And at last - that would be a very good thing. It's amazing to think
that we were doing vector transparency 12 years ago, and still the world
hasn't caught up with this. I hope it's not going to be another 12
before they discover the merits of graduated vector transparency
(although this can be simulated with masks).

> I don't know Xara well enough but if its transparency 
> features are reasonably mappable to PDF transparency model, 
> then it would be a shame to go over PostScript for printing 
> on longer term. More and more RIPs are handling transparency 
> natively (instead of doing an internal PDF->PS conversion and 
> using their classic PS channel), especially with Adobe's 
> recent PDF Print Engine product.

It's a reasonable map for a subset of our transparency modes, but
thankfully these are the commonly used transparency types. And this is
why our PDF 1.4 output is good, because we do map to native PDF
equivalents.

Charles