\documentclass{book}
\usepackage{lmodern}
\usepackage[T1]{fontenc}
\usepackage[protrusion=false,expansion=true,stretch=8,shrink=24,step=4]{microtype}
\makeatletter
\renewcommand\normalsize{\@setfontsize\normalsize{8}{4mm}}\makeatother
\small \normalsize
\usepackage[c8,margins=6mm,headheight=4mm,headsep=4mm,adjustheadsep,
   croplength=3mm,cropgap=2mm,
   cropmarks,cropframe,croptitle=Adjust\ headsep]{zwpagelayout}

\markboth{Sample page}{Sample page}

\begin{document}
\input{LoremIpsumDolor}
\end{document}
