
\lipsum*[1]
\begin{tikzpicture}[remember picture,overlay]
  \clip (current page.south west) rectangle (current page.north east);
  \draw [line width=2pt] ([shift={(.5\pgflinewidth,.5\pgflinewidth)}]current page.south west) rectangle ([shift={(-.5\pgflinewidth,-.5\pgflinewidth)}]current page.north east);
\end{tikzpicture}

\lipsum[2-5]

