%%
%% The LaTeX Companion, 3ed
%%
%% Example 5-5-1 on page I-410 in "draftwatermark --- Put a visible stamp on your document".
%%
%% Copyright (C) 2022 Frank Mittelbach
%%
%% It may be distributed and/or modified under the conditions
%% of the LaTeX Project Public License, either version 1.3c
%% of this license or (at your option) any later version.
%%
%% See https://www.latex-project.org/lppl.txt for details.
%%

\documentclass{tlc3exa}
\pagestyle{empty}
\setcounter{page}{6}
\setlength\textwidth{124.20126pt}


  \pagestyle{origplain}   % example class does not show page numbers with ``plain'' pagestyle
  \setcounter{page}{1}

  \tolerance=4000          % examples is very narrow ...
  \usepackage{microtype}   % so let's try to make this a bit better

  %--------------------------------------
  % For the book example we have to do some faking here. By default the
  % hpos and vpos are at the center of the page and so we mimic this
  % here. This is why we load the package internally and reset the keys:

  \setlength\textheight{94pt}
  \setlength\oddsidemargin{0pt}
  \setlength\evensidemargin{0pt}

  \RequirePackage{draftwatermark}
  \DraftwatermarkOptions{
    hpos=\dimexpr 1in + .5\textwidth ,
    vpos=\dimexpr 1in + \topmargin + \headheight+\headsep+ (\textheight+\footskip)/2 ,
  }

  % So the above should not be copied into your own document preamble.
  %--------------------------------------


%StartShownPreambleCommands
\usepackage{lipsum,xcolor}
\usepackage{draftwatermark}
\DraftwatermarkOptions
  {fontsize=25pt,colorspec=.6}

%StopShownPreambleCommands

\begin{document}
\lipsum[1][1-3]
\newpage
\DraftwatermarkOptions
  {color=blue!40, angle=-45,
   text=Private, scale=1.4 }
\lipsum[2][1] \par \lipsum[3]
\end{document}