% Source: http://tex.stackexchange.com/a/131459/23931
\documentclass[pstricks,border=12pt]{standalone}
\newpsstyle{gridstyle}
{
gridlabels=0,
gridwidth=6pt,
subgriddiv=1,
gridcolor=gray,
}
\begin{document}
\begin{pspicture}(8,8)
\psframe*(8,8)
\psgrid[style=gridstyle]
\psset{linecolor=white}
\multips(0,1)(0,1){7}{\multips(1,0)(1,0){7}{\qdisk(0,0){4.242pt}}}
\end{pspicture}
\end{document}
