Typography with TeX and LaTeX

## center vs. \centering

Juni 13th, 2008 by Stefan Kottwitz

A frequently seen mistake is to use \begin{center} … \end{center} inside a figure or table environment. This center environment can cause additional vertical space. If you want to avoid that just use \centering instead like in this example:

\begin{figure}[ht] \centering \includegraphics{filename}% \caption{text}% \end{figure}

The additional space of the center environment is caused by a trivlist environment. Its defined by latex.ltx:

\def\center{\trivlist \centering\item\relax} \def\endcenter{\endtrivlist}

As you can see \center calls \centering too. By directly using \centering you could omit that trivlist.

Inside normal text \begin{center} … \end{center} is useful of course to center and to generate vertical space between the centered text and the surrounding text.

Concerning \centering it’s advisable to limit its scope by grouping. Inside a figure or table environment it’s already limited, but inside normal text you should use curly braces or \begingroup\centering … \endgroup:

{\centering Text   }

As you can see I set an empty line before closing the centered group. If I do not end the paragraph by a paragraph break or the line by \\ then the following text outside the group will be centered too. \centering is also defined by latex.ltx:

\def\centering{% \let\\\@centercr \rightskip\@flushglue\leftskip\@flushglue \parindent\z@\parfillskip\z@skip}

It’s using \leftskip and \rightskip to flush left and right.

This topic was discussed in the LaTeX Community Forum, on mrunix.de and on ubuntuusers.de .

This entry was posted on Freitag, Juni 13th, 2008 at 07:05 and is filed under Layout. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.

### 6 responses about “center vs. \centering”

1. oconnoat.com » Blog Archive » Automatic Table Row Numbers in LaTeX said:

[…] be better than using begin{centre}. For those of you who are interested, here is an article on the centering vs. centre issue. My thanks go out to Stefan_T for his help! posted under […]

2. Yoo said:

> … then the following text outside the group will be centered too.

Is this a bug? Why does it do this?

3. none said:

@Yoo:

No, it’s just because \center is a switch: you switch on centered typesetting. Unless it’s turned off again (switched to left-aligned, say), LaTeX will continue centering. Everything’s fine there. The scope is a paragraph, as determined by the TeX engine.

4. lolo said:

how to end centering?

5. ATTN: Studenten steun- en klaagthread - Deel 22 - Pagina 117 - 9lives - Games Forum said:

[…] geplaatst door edraket doe es begin{center} en end{center} rond uw includegraphics? center vs. centering - TeXblog - Typography with TeX and LaTeX Voor de rest: begin{figure}[htb] centering includegraphics[width=0.9textwidth]{awesomeimage} […]

6. Tingting said:

Just give it a scope {\centering …}