Floats in multicolumn setting

If you use

\begin{figure}
  ...
\end{figure}

in a multicols environment, the figure won’t appear. If instead you use

\begin{figure*}
  ...
\end{figure*}

the figure will stretch right across the page (just the same as a figure* in standard LaTeX’s twocolumn option).

It’s possible to have single-column figures and tables with captions, using the ‘[H]’ placement option introduced by the float package but you might have to fiddle with the placement because they won’t ‘float’, and exhibit other strange behaviours (such as silently running off the end of the column at the end of the multicols environment).

float.sty
macros/latex/contrib/float (or browse the directory); catalogue entry
multicol.sty
Distributed as part of macros/latex/required/tools (or browse the directory); catalogue entry

This question on the Web: http://www.tex.ac.uk/cgi-bin/texfaq2html?label=mcfloat