%%% Local Variables:
%%% coding: utf-8
%%% mode: latex
%%% TeX-engine: xetex
%%% End:

\documentclass{standalone}
\usepackage{xltxtra}
\usepackage{tikz}

\setmainfont{Helvetica Neue}

\begin{document}

\tikz {
  \draw[draw=none,fill=black!20!white] (-100,-100) rectangle (100,100);
  \node[text=white,scale=250.0] at (0,0) {ZW};
}

\end{document}