# Background image on every page with tikz

I'd like to get a background image on every page of a document, but I just get it on the first page with the following code!

\documentclass[11pt]{article}
\usepackage{fullpage, lipsum, tikz}

\begin{document}
\tikz[remember picture, overlay] \node[opacity=.1, inner sep=0pt] at(current page.center){\includegraphics[width=14cm, angle=45]{pic.png}};
\lipsum[1-20]
\end{document}


You can use eso-pic for that. (There are also specific watermark packages available but this might be one of the easiest ways to retain full control. Please note that I do not have pic.png so I replaced it by a generic picture. You may also want to use geometry instead of fullpage.)

\documentclass[11pt]{article}
\usepackage{fullpage, lipsum, tikz}
\usepackage{eso-pic}