# subtitles in tcolorbox like in mdframed

Until now, I have used mdframed to produced nice framed boxes. I recently discovered tcolorbox, and found that it has several advantages over mdframed. In my actual and future work I would prefer tcolorbox. Nevertheless, one nice thing in mdframed is the \mdfsubtitle. You can divide a framed box into several "sections" with nice formatted titles, as seen in the picture (copied from the mdframed documentation):

My Question: is there a (more or less) simple way of having such subtitles with tcolorbox?

• Welcome to TeX.SE. You can have exactly one upper and one lower box with the tcolorbox command. However, you can nest boxes – user31729 Apr 23 '14 at 14:52

As far as I know there are no direct options like in mdframed but you can easily build your subtitle box.

\documentclass{article}
\usepackage{tcolorbox}
\tcbuselibrary{skins}

\newtcolorbox{mybox}{
enhanced,
bottom=1pt,
top=1pt,
arc=0pt,
boxrule=.4pt,
before=\vskip6pt,
colback=yellow!70!white,
oversize
}

\begin{document}
\begin{tcolorbox}[title=Theorem,colbacktitle=yellow!70!white,colback=blue!20!white,coltitle=black]
Some text ...
\begin{mybox}
test
\end{mybox}
some text
\end{tcolorbox}
\end{document}


The idea is to create a custom tcolorbox (mybox in the mwe) that you'll use as a subtitle box. Every time you want a subtitle just nest a mybox into your main box and you're set. The inner boxes use the oversize key which removes the margin of the outer box giving the desired effect.

tcolorbox now has a \tcbsubtitle option:

## Code:

\documentclass{article}
\usepackage{tcolorbox}
\tcbuselibrary{skins}

\newtcolorbox{mybox}{
enhanced,
bottom=1pt,
top=1pt,
arc=0pt,
boxrule=.4pt,
before=\vskip6pt,
colback=yellow!70!white,
oversize
}

\begin{document}
\begin{tcolorbox}[title=Theorem,colbacktitle=yellow!70!white,colback=blue!20!white,coltitle=black]
Some text ...
\tcbsubtitle{test}
some text
\end{tcolorbox}
\end{document}

• I discovered this feature recently. It's nice to have subtitles directly implemented into the package. – Michael P May 17 '18 at 11:24