# tabucline with a break

In the following the first two columns are different in nature from the last two and I wanted to emphasize this by having a break in the horizontal line. I drew lines across columns 1 and 2 and then across 3 and 4 but they connect up. How can I get some space between them so that there are two distinct horizontal line segments? If possible I would like to stick with using tabu.

\documentclass{article}
\usepackage{tabu}
\begin{document}

\begin{center}
\begin{tabu}{XXXX}
1 & 2 & a & b\\
\tabucline{1-2 3-4}
1 & 2 & a & b\\
\end{tabu}
\end{center}

\end{document}


Output (ok except I would like some space in the horizontal line between column 2 and 3):

-

You can use \cmidrule from the booktabs package which provides a method of shortening each end:

## Code:

\documentclass{article}
\usepackage{booktabs}
\usepackage{tabu}
\begin{document}

\begin{center}
\begin{tabu}{XXXX}
1 & 2 & a & b\\
\cmidrule(r{1.0ex}){1-2}\cmidrule(l{1.0ex}){3-4}
1 & 2 & a & b\\
\end{tabu}
\end{center}
\end{document}

-
Thanks. I should have included the fact that the rule is in color since that was part of my \tabucline command before I made the example minimal but it seems that \arrayrulecolor{red} placed before the cmidrule line does work so I am ok after all. – user1189687 Jul 22 '12 at 22:26
Is there a solution that does not require booktabs? In another question it was pointed out in tex.stackexchange.com/questions/64332/… that there is a problem with using booktabs with tables having color. – user1189687 Jul 23 '12 at 3:37
@user1189687: I do not know, but I am not an expert on tables by any means... – Peter Grill Jul 23 '12 at 3:55