Three-columns text with figures of 2\columnwidth

Although in multicol environment (not the twocolumn option in document class) is problematic to place floats, there are some ways to put figures within a single column or occupying the entire width of the text. (That is not the problem)

But how manage figures that must be fitted in 2 columns when there are 3 columns? (ie, images fitted to about 0.65\textwidth after a \begin{multicols}{3}). There are some solution with or without multicol package?

This is a usual design in some books and journals and it is hard to believe that there are no document class, packages nor some clever trick to obtain this. For a single page I suppose that doing some ad hoc manual arrangements, with minipages for example, might be enough, but for a large document this approach would be a torture, so my question is about a general solution.

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Maybe flowfram helps. –  Stephan Lehmke Sep 5 '12 at 5:59
Thanks Stephan. Now I have no time to study the package, but looks great. –  Fran Sep 5 '12 at 10:51
@StephanLehmke, it seems that nobody knows another solution. Please convert your comment in answer to accept it. –  Fran Sep 16 '12 at 19:19

In case that might be useful for someone, here are a MWE using flowfram as suggested by Stephan Lehmke. Is not comparable to a elegant float of width = n-x columns, but solved the problem.

\documentclass{article}
\usepackage[demo]{graphicx} % Demo for MWE
\usepackage[landscape,margin=1cm]{geometry}
\usepackage{color}
\usepackage{flowfram}
\usepackage{lipsum}
\usepackage{microtype}

\newflowframe[1-7]{0.30\textwidth}{\textheight}
{0pt}{0pt}[leftcolumn]

\newflowframe[2,4-7]{0.30\textwidth}{\textheight}
{0.35\textwidth}{0pt}[centercolumn]

\newflowframe[2,4-7]{0.30\textwidth}{\textheight}
{0.7\textwidth}{0pt}[rightcolumn]

\newflowframe[1,3]{0.30\textwidth}{.6\textheight}
{0.35\textwidth}{0pt}[shortcentercolumn]

\newflowframe[1,3]{0.30\textwidth}{.6\textheight}
{0.7\textwidth}{0pt}[shortrightcolum]

\newstaticframe[1]{0.65\textwidth}{.35\textheight}
{0.35\textwidth}{.65\textheight}[statico]

\newstaticframe[3]{0.65\textwidth}{.35\textheight}
{0.35\textwidth}{.65\textheight}[statico2]

\usepackage{caption}

\title{\textbf{Flowfram demo}}
\author{by Fran}
\date{\today}

\begin{document}

\maketitle

{\color{blue} The dummy text of this MWE flow freely
through three columns in four pages. In pages 1 and 3 the
two landscape images have a width of two columns.}
\bigskip

\lipsum[1]

\begin{figure}[hb]
\includegraphics[width=.3\textwidth]{figure.png}
\caption{This is a float -- here -- figure.}
\end{figure}

\begin{staticcontents*}{statico}
\includegraphics[width=\textwidth,
height=0.32\textheight]{figure.png}\\
\captionof{figure}
{This is a non float image in a static frame.}
\end{staticcontents*}

\begin{staticcontents*}{statico2}
\includegraphics[width=\textwidth,
height=0.32\textheight]{figure.png}\\
\captionof{figure}
{This is another landscape in another static frame.}
\end{staticcontents*}

\lipsum[2-3]

\begin{figure}[h]
\includegraphics[width=.3\textwidth]{figure.png}
\caption{Other float -- here (bottom) -- figure.}
\end{figure}

\lipsum[4-35]

\end{document}

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I see one huge disadvantage, it is not on the grid, check more: wiki. You should add vertical spaces to achieve baseline grid layout, check more: baseline grid. I don't know any out-of-the-box solution in LaTeX, that can provide this. –  random.nick Oct 10 '13 at 3:42
@random.nick This was a question about mixing columns and floats, in no way related with the grid system. You can find questions and answers about this style of typography under the tag grid-typesetting. –  Fran Oct 10 '13 at 18:25
I understand, but grid is elementary in typography. It is not a style, it is something very fundamental. So it is related to this and every other question:) You can try to use grid package, if you want. –  random.nick Oct 12 '13 at 12:26