Voici une solution basée sur un exemple à la page 174 de la documentation de l'extension [tcolorbox](https://www.ctan.org/pkg/tcolorbox) \documentclass{article} \usepackage[most]{tcolorbox} \usepackage{mwe} \begin{document} \lipsum[1-3] \begin{tcolorbox}[enhanced, breakable, colback=white,colframe=white, size=minimal, %boxsep=0pt, boxrule=0pt, %top=0pt, bottom=0pt,left=0pt, right=0pt, overlay={% \begin{tcbclipinterior} \draw[red,line width=.2cm] (interior.north west)--(interior.south east); \draw[red,line width=.2cm] (interior.south west)--(interior.north east); \end{tcbclipinterior}}] \lipsum[1-7] \end{tcolorbox} \lipsum[1-4] \end{document} En feuilletant la documentation j'ai découvert que l'option `blank` permet de cacher les éléments graphiques de la boite. Voici un deuxième exemple utilisant cet option et `\newtcolorbox`. \documentclass{article} \usepackage[most]{tcolorbox} \newtcolorbox{barrer}{blank,breakable, overlay={% \begin{tcbclipinterior} \draw[red,line width=.2cm] (interior.north west)--(interior.south east); \draw[red,line width=.2cm] (interior.south west)--(interior.north east); \end{tcbclipinterior}}} \usepackage{mwe} \begin{document} \lipsum[1-3] \begin{barrer} \lipsum[1-7] \end{barrer} \lipsum[1-4] \end{document}

Voici une solution basée sur un exemple à la page 174 de la documentation de l'extension [tcolorbox](https://www.ctan.org/pkg/tcolorbox) \documentclass{article} \usepackage[most]{tcolorbox} \usepackage{mwe} \begin{document} \lipsum[1-3] \begin{tcolorbox}[enhanced, breakable, colback=white,colframe=white, size=minimal, %boxsep=0pt, boxrule=0pt, %top=0pt, bottom=0pt,left=0pt, right=0pt, overlay={% \begin{tcbclipinterior} \draw[red,line width=.2cm] (interior.north west)--(interior.south east); \draw[red,line width=.2cm] (interior.south west)--(interior.north east); \end{tcbclipinterior}}] \lipsum[1-7] \end{tcolorbox} \lipsum[1-4] \end{document}