Is it possible to change the line spacing within a colchunk in a parcolumns environment? I tried the following without success:
\documentclass{article}
\usepackage{parcolumns}
\begin{document}
\renewcommand{\baselinestretch}{1.5}\normalsize
\begin{parcolumns}[nofirstindent]{2}
\colchunk[1]{bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla bla}
\colchunk[2]{\renewcommand{\baselinestretch}{1.1}\footnotesize This works not. This works not. This works not. This works not. This works not. This works not. This works not. This works not. This works not. This works not. \par}
\colplacechunks
\end{parcolumns}
{\renewcommand{\baselinestretch}{1.1}\footnotesize This works fine. This works fine. This works fine. This works fine. This works fine. This works fine. This works fine. This works fine. This works fine. This works fine. \par}
\end{document}

parcolumnsenvironment, all this was irrelevant for the original question. It is only relevant for Keks Dose's recommendation of theparacolpackage. – Dieter May 08 '12 at 21:45