Fontspec transparency problems

Question

I'm using this minimal document to test transparency:

\documentclass[11pt]{article}
\usepackage{xunicode, xltxtra}
\defaultfontfeatures{Mapping=tex-text}
\usepackage{fontspec}
\usepackage[usenames]{xcolor}

\begin{document}
\fontspec[Color=red,Opacity=0.1,Scale=12]{Helvetica}Test
\end{document}

The rendered text is fully opaque when typeset through TeXShop with TeXLive 2011 on a MacOS Lion. Is this a known issue?

Answer 1

From the fontspec manual (p.16):

Transparency is supported by LuaLaTeX and by XeLaTeX with the xdv2pdf driver (Mac OS X only); XeLATeX with the xdvipdfmx driver does not support this feature.

TeXShop has an engine for compiling XeLaTeX with the xdv2pdf driver. You can activate it by dragging it from the ~/Library/TeXShop/Engines/Inactive folder to the Engines folder. Compiling your document with this driver gives the desired transparency.

I don't think, however, that this driver is actively supported anymore, (the xdvipdfmx driver is the default) so it's unclear if using it will affect other things.