\documentclass[a4paper,10pt]{scrartcl}
\input{Base.tex}
\begin{document}
\begin{figure}[ht]
\centering
\begin{tikzpicture}[x=1cm,y=1cm]
\draw[step=5mm,light-gray,line width=0.1pt] (0,0) grid (20.5,29.5);
\end{tikzpicture}
\end{figure}
\end{document}