# shrink page to allow optional annotations or margin notes

I am working on a lab manual that will have a student version and an instructor version. I'd like the instructor version to be like an annotated copy of the student version, perhaps with the content from each page of the student version shrunk into a box that can have instructor notes around it. For some pages there is as much additional annotation for the instructors as their is content for the students, so I can't just cram it into a margin or vertical space that is left blank on the student version as it would leave lots of weird white space in the student version. If I include the annotations inline on the instructor version the content in the two versions will have different lengths and the page numbering will get out of sync (i.e. the content on page 5 of the instructor manual could be on page 4 of the student manual) which I want to avoid.

Is there a package or method that anyone can recommend that will shrink the content on a page (without repaginating) to allow space for margin notes or annotations when turned on.

Document with \iffalse and \iftrue respectively.

\documentclass{article}
\iftrue
\setlength\marginparwidth{15cm}
\mag500
\else
\long\def\marginpar#1{}
\fi
\usepackage{graphicx}

\def\x{One two three\stepcounter{enumi}\roman{enumi}, four five six. }
\def\y{\x\marginpar{\large
a really long annotation about   something
a really long annotation about   something
\begin{itemize}
\item sss sss sss sss sss sss sss sss sss sss sss sss sss
\item jjj jjj jjj jjj jjj jjj jjj jjj jjj jjj jjj jjj jjj jjj
\end{itemize}}\x\x Red yellow blue green \x\x\x}
\def\z{\x\y\x\par\x\x\x\x\x\x apple orange pear \y\x\x\x\x\x\y}

\begin{document}

\section{aaa}
\z\x\x

\x\x\x\x

\section{bbb}
\x\y\z

\section{ccc}
\x\x\x\y\z

\end{document}