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

[Philip TAYLOR (Webmaster, Ret'd)]

Peter Dyballa wrote:
>
> Am 05.06.2011 um 21:24 schrieb Philip TAYLOR (Webmaster, Ret'd):
>
>> So how is it, I am forced to ask, that an add-on package can achieve 
>> something that the underlying
>> engine cannot ?  This seems very odd to me.
>
> The fontspec package does not use PDF specials which TiKZ/PGF uses. 
> That's my simply explanation. It has built-in transparency support 
> which is built-in into Mac OS X. Xdvipdfmx does not use this (yet).

Yes, but I'm not using the fontspec package.  I am using the raw \font
primitive provided by XeTeX.  Now if TikZ/PGF can achieve transparency
using the XeTeX engine with xdvipdfmx, then the underlying engine must
be able to do the same thing.  So why doesn't it ?!

** Phil.