LaTeX table: line thickness varying and incorrect horizontal alignment

Question

This LaTeX source ( http://pastebin.com/3HdpbQi5 ) yields two types of errors ( http://i.stack.imgur.com/4J87t.png ):

The line thickness of the table borders in the primary header row varies and the last entry in the secondary header-row ("erh.", short for "erhalten" which means "received" :) is a good few points above where it should be.

Now, knowing that LaTeX does not err, I however do so quite frequently - any ideas what I can do to get a clean result? The whole thing, btw., is a ham radio logbook in case you wondered.

Thanks in advance,

Christian DC1TS.

Answer 1

I guess the culprits are your strange column specifications. Why not "|c|c|c|c|..."?

Anyway, you can work around the layout problems by omitting the left vertical line of the multicolumns

\multicolumn{2}{c|}{Zeit UTC} &

and putting the last column inside one

\multicolumn{1}{c|}{erh.} \\ [1ex]

But these are just workarounds to fix the layout momentarily, you should try to understand what's going on.

Answer 2

a multicolumn should only define the right vertical line {c|}, except for the very first column, there a {|c|} is correct. Otherwise you'll get two vertical lines.

\documentclass[ngerman,12pt,a4paper,oneside,landscape]{article}
\usepackage[utf8]{inputenc}
\usepackage[a4paper, left=0.5cm, right=0.5cm,top=1cm, bottom=0.5cm]{geometry}
\usepackage{babel}
\usepackage[table]{xcolor}
\usepackage{todonotes}
\usepackage{array,ragged2e}
\newcolumntype{M}[1]{>{\Centering}m{#1}}
\begin{document}

\rowcolors{3}{gray!10}{white}
\begin{tabular}{
| m{2cm} %Datum
| m{1.3cm}  %Zeit Start
| m{1.3cm}  %Zeit Ende
| m{2cm}  %Frequenz
| m{1.5cm}  %Mode
| m{3cm}  %Rufzeichen
| m{3cm}  %Name
| m{3cm}  %QTH
| m{1.3cm} %Power
| m{0.9cm} %Report gegeben
| m{0.9cm} %Report erhalten
| m{0.8cm} %QSL gesendet
| m{0.8cm} %QSL erhalten
|} 
\hline 
Datum & 
\multicolumn{2}{c|}{Zeit UTC} & 
Frequenz & 
Mode & 
Rufzeichen & 
Name & 
QTH & 
Power & 
\multicolumn{2}{c|}{Report} & \multicolumn{2}{c|}{QSL}  \\ [1ex]
& Start & Ende & (MHz) &  &  & & & (W) & geg. & empf. & ges. & erh. \\ [1ex]
\hline
 & : & : & & & & & & & & & & \\ [4ex]\hline 
 & : & : & & & & & & & & & & \\ [4ex]\hline 
 & : & : & & & & & & & & & & \\ [4ex]\hline 
 & : & : & & & & & & & & & & \\ [4ex]\hline 
 & : & : & & & & & & & & & & \\ [4ex]\hline 
 & : & : & & & & & & & & & & \\ [4ex]\hline 
 & : & : & & & & & & & & & & \\ [4ex]\hline 
 & : & : & & & & & & & & & & \\ [4ex]\hline 
 & : & : & & & & & & & & & & \\ [4ex]\hline 
 & : & : & & & & & & & & & & \\ [4ex]\hline 
 & : & : & & & & & & & & & & \\ [4ex]\hline 
 & : & : & & & & & & & & & & \\ [4ex]\hline 
\end{tabular}

\end{document}