Are you trying to make a poster (or presentation), or any ordinary writing doc? I have done a poster where I put a \usebackgroundtemplate in Beamer. In that case my attempt was successful.
. If you are trying to do this type, I can send you my script...or in a short form it is --
\documentclass[final, 12pt]{beamer}
\usepackage[size=custom,width=77,height=107,scale=1.4,orientation=portrait]{beamerposter}
\usepackage[english]{babel}
\usepackage{graphicx}
\usepackage{wrapfig,xcolor}
\usepackage{array,booktabs,tabularx,amsthm,multirow,amsmath}
\usepackage[absolute,overlay]{textpos}% text under figure
\usepackage{fancybox}%different shape box
\usepackage{mdframed}%framed
\usepackage{tikz}
\usebackgroundtemplate{\centering \includegraphics[width=\paperwidth, height=120cm]{AGC_figure/P-1.jpg}}
\addtobeamertemplate{block begin}{\pgfsetfillopacity{0.85}}{\pgfsetfillopacity{1}}
\newenvironment<>{varblock}[2][\textwidth]{%
\setlength{\textwidth}{#1}
\begin{actionenv}#3%
\def\insertblocktitle{#2}%
\par%
\usebeamertemplate{block begin}}
{\par%
\usebeamertemplate{block end}%
\end{actionenv}}
\usecolortheme{rose}
\setbeamercolor{uppercolgreen}{fg=white,bg=green!35}%Using this you can change the box color
\setbeamercolor{lowercolgreen}{fg=black,bg=green!10}
\setbeamercolor{eecks} {bg=white, fg=black}
\setbeamercolor{eecks2}{bg=white, fg=blue}
\setbeamercovered{transparent=80!}
\begin{document}
\begin{frame}
\pgfsetfillopacity{0.85}
\begin{textblock}{}(0.2,1.1)%
\begin{varblock}[35cm]{\textbf{1. Introduction}}
\begin{wrapfigure}[4]{r}{6.8cm}
\centering
\vspace{-2cm}
\includegraphics[height=5cm]{AGC_figure/P-2.pdf}
\end{wrapfigure}
\end{varblock}
\end{textblock}
\begin{textblock}{}(0.2,3.55)%
\begin{varblock}[34cm]{\textbf{3. Site \& Equipment}}
-------------------------------------------------------------------------------------------------------------------------------------------your text-------------------------------------
\begin{wrapfigure}[7]{l}{10.5cm}
\vspace{-1cm}
\centering
\hspace{-1cm}
\includegraphics[height=7.5cm]{AGC_figure/P-3.pdf}
\end{wrapfigure}
{conditions.}
\end{varblock}
\end{textblock}
\end{frame}
\end{document}
\documentclass{...}
and ending with\end{document}
.wallpaper
package can help you with background images.