答案1
你的问题不太生动,但我更喜欢tikz
和atbegshi
。
\documentclass{article}
\usepackage{tikz}
\usepackage{atbegshi}
\usepackage{lipsum}
\usepackage{multicol}
\AtBeginShipout{\AtBeginShipoutAddToBox{%
\begin{tikzpicture}[remember picture, overlay]
\draw [fill=gray, opacity=.3] (\marginparwidth-\marginparsep, -\headheight-\headsep) rectangle
(\marginparwidth+\columnwidth,-\textheight-\headheight-2\headsep);
\end{tikzpicture}%
}}
\begin{document}
\begin{multicols}{2}
\lipsum[1-40]
\end{multicols}
\end{document}