Dot graph paper in LaTeX

dotgraph.tex

\documentclass{article}
\pagenumbering{gobble}
\usepackage[a4paper,hmargin={0mm,3mm},vmargin=5mm]{geometry}  
\usepackage{tikz}
\begin{document}
  \begin{tikzpicture}[scale=.5]
    \foreach \x in {0,...,41}
    \foreach \y in {0,...,57}
    {
  \fill[gray!75] (\x,\y) circle (0.06cm);
    }       
  \end{tikzpicture}
\end{document}