eso-pic
该包可以帮助您在背景上添加蓝线。
\documentclass{book}
\usepackage{eso-pic}
\usepackage{lipsum}
\title{This is the title}
\author{me}
\begin{document}
\AddToShipoutPictureBG*{
\AtPageLowerLeft{%
\color{cyan}%
\rule{2cm}{\paperheight}%
}
}
\maketitle
\chapter{1}
\lipsum[1]
\end{document}
![在此处输入图片描述](https://i.stack.imgur.com/xfEoQ.png)