# make soul highlight span lines

The \hl command from the soul package highlights spans of text with a backround color when color is loaded. When used on longer spans of text, some inter-line spacing remains uncolored, which is rather unpleasant to my eye.

\documentclass[a8paper, landscape]{scrartcl}
\usepackage{color, soul}
\sethlcolor{red}
\begin{document}
This is some text \hl{of that some part should be highlighted. This part spans multiple lines}, which is easy on a8paper.
\end{document}


I already tried to tinker with \setul, but increasing the height and depth there just enlarges the line height, leaving unchanged the spacing in between.

Is there a way to have the result look like this?

Answers do not have to be restricted to the package. (Meaning soul-less answers are also welcome. ;)

A non-soul approach can be found in wrapping inline long lines and adding background color

But it is impossible to re-create with a few macros all the job done by soul.(*) Here is a customization of soul's highlighting driver which seems to obtain what is required:

(*) besides the solutions linked to above seem to be using only monotype font.

\documentclass[12pt, a4paper, landscape]{scrartcl}
\usepackage{color, soul}
\sethlcolor{red}
\makeatletter
\def\SOUL@hlpreamble{%
\setul{\dp\strutbox}{\dimexpr\ht\strutbox+\dp\strutbox\relax}%
\let\SOUL@stcolor\SOUL@hlcolor
\SOUL@stpreamble
}
\makeatother

\usepackage[textwidth=10cm]{geometry}
\usepackage{multicol}

\begin{document}
\begin{multicols}{3}\raggedcolumns
This is some text \hl{of that some part should be highlighted. This part
spans multiple lines}, which is easy on a8paper.
\columnbreak

This is some text {of that some part should be highlighted. This part
spans multiple lines}, which is easy on a8paper.
\columnbreak

This is some text \hl{of that some part should be highlighted. This part
spans multiple lines}, which is easy on a8paper.
\end{multicols}
\end{document}