I was trying to create a tikzpicture environment which includes external graphics (as a PDF). The external graphics should be translucent, so I used the opacity parameter. Using pdfLaTeX it works as expected, but under XeLaTeX (which I need for other reasons) there is no transparency. After checking some more, it appears to work fine under XeLaTeX for JPGs and (more importantly) EPS. If no more elegant solution can be found, I can use EPS graphics instead of PDF. But maybe there is a magical definition I can put in the header to fix this?
Here is the MWE:
\documentclass{article}
\usepackage{tikz}
\begin{document}
\begin{tikzpicture}% Regular figure
{\node{\includegraphics{pdfgraphics.pdf}};}
\end{tikzpicture}%
\begin{tikzpicture}% Pale figure
{\node[opacity=0.3] {\includegraphics{pdfgraphics.pdf}};}
\end{tikzpicture}%
\end{document}
And here are the results when using both engines:
