\documentclass[12pt,a4paper]{article}
\usepackage{geometry}
\geometry{margin=0.25cm}
\usepackage{tikz}
\begin{document}
  \begin{titlepage}
  \noindent\centering
  \begin{tikzpicture}
    \draw[line width=0.5pt,step=0.1cm] (0,0) grid (20,29);
    \draw[line width=1.5pt] (0,0) grid (20,29);
  \end{tikzpicture}
\end{titlepage}
\end{document}

\documentclass[12pt,a4paper]{article}
\usepackage{geometry}
\geometry{margin=0.25cm}
\usepackage{tikz}
\begin{document}
  \begin{titlepage}
  \noindent\centering
  \begin{tikzpicture}
    \draw[line width=1pt,step=1cm] (0,0) grid (10,10);
  \end{tikzpicture}\hskip8pt
  \begin{tikzpicture}
    \draw[line width=1pt,step=1cm] (0,0) grid (10,10);
  \end{tikzpicture}\\[8pt]
  \begin{tikzpicture}
    \draw[line width=1pt,step=1cm] (0,0) grid (10,10);
  \end{tikzpicture}\hskip8pt
  \begin{tikzpicture}
    \draw[line width=1pt,step=1cm] (0,0) grid (10,10);
  \end{tikzpicture}
\end{titlepage}
\end{document}