[XeTeX] "Options for all fonts" : colo[u]r, and the transparency byte

[Philip TAYLOR (Webmaster, Ret'd)]

Thank you for your further comments, Mathew :

mskala at ansuz.sooke.bc.ca wrote:
>
> The default driver for XeTeX is xdvipdfmx; you're probably already using
> it, so that's most likely not your problem.

Yes, this is a XeTeX-specific question (I need non-TeX fonts), so I am using
the XeTeX default driver.
>
> My next guess would be that there may be an issue with whatever you're
> using to view the resulting .pdf file.

Same results in the TeXworks previewer, Adobe Reader 10.x and Adobe 
Acrobat 7.x
>
> You may be able to check the version of your PDF files with the "file" or
> "pdfinfo" commands.  My transparency-containing PDFs are reported
> as version 1.5.
>    

V1.5 (see below)

E:\TeX\Projects\Tests\TAR>pdfinfo TAR-1.pdf
Creator:         XeTeX output 2011.06.05:1514
Producer:       xdvipdfmx (0.7.8)
CreationDate:   06/05/11 15:14:36
Tagged:         no
Pages:          1
Encrypted:      no
Page size:      841.89 x 595.28 pts (A4)
File size:      25465 bytes
Optimized:      no
PDF version:    1.5

> Another thing to try:  it's possible that using a transparent colour for
> your text with the "color=" feature doesn't work even if using some other
> route to transparency would work.  I tried to reproduce your problem and
> realized that the feature whose documentation you quoted from is a Plain
> XeTeX feature associated with the "\font" command.  I'm not familiar
> enough with that low-level command to test it reliably; the approach I've
> used, which has worked for me, is to use transparency at the level of TikZ
> (they call it "opacity", which is just the inverse) in LaTeX, something
> like this:
>
> \begin{tikzpicture}
>    \node[color=blue,opacity=0.2] at (0,0) {Blah blah};
> \end{tikzpicture}
>
> I think it'd be worth trying to set the colour and opacity in that way
> rather than through the low-level \font command.
>    

YES :-)))  Finally it works.  As I am already using TikZ because I also need
text-along-a-path, this solution is perfect.  Thank you very much indeed
(but of course I would dearly love to know why the documented RGBA
specifier for the font colour does not work !).
> Make sure your print shop can handle transparency.  If they can't, you'll
> be wasting your time trying to resolve the software issues on your own
> end.  I've heard professional designers claim snarkily that any shop that
> can't handle (the very latest bleeding-edge optional features of...)
> standard formats shouldn't be in the business, but it's a fact that many
> shops who deal with the general public (e.g. Lulu, and Amazon CreateSpace)
> insist resolving transparency should be the customer's problem, not theirs.
>    

Unfortunately I am separated from the print shop by an intermediary
(the son of the shop owner), and I haven't even heard back from him
whether my first attempts (using Paintshop Pro X) will be suitable or
whether I need to pursue this XeTeX/TikZ route at all ...
> Is it *really* prohibitive to rasterize?  The resulting file sizes
> shouldn't be all that bad, because of compression, and anyone with a
> printer that handles huge media ought to be able to deal with files of the
> size doing so requires.  They have to print photos on their printer once
> in a while, and as soon as they do, they'll be handling files larger
> than yours.
>    
I have no idea how the print shop will produce a 7m-long sign; for now,
I leave that up to them !  But at least I can now produce both 
text-on-a-path
and transparency, so I feel that there is at last light at the end of 
the tunnel.
Once again, many many thanks.

Philip Taylor