Tables, Cellcolor and horizontal lines

Question

I don't understand why my lines aren't showing up or look funny in this minimal example

\documentclass{article}
\usepackage[table]{xcolor}
\usepackage{hhline}

\begin{document}

 \begin{center}
 \begin{tabular}{|cc|p{1in}|cc|p{1in}|cc|} \hhline{--~--~--}
 \multicolumn{2}{|c|}{\cellcolor{green!50!white}U.S.} &&\multicolumn{2}{|c|} 
 {\cellcolor{green!50!white}France}&&\multicolumn{2}{|c|} 
 {\cellcolor{green!50!white}Japan} \\ \hhline{--~--~--}
 \multicolumn{2}{|c|}{$8$} &&\multicolumn{2}{|c|}{$41\frac{1} 
 {3}$}&&\multicolumn{2}{|c|}{$260$} \\ %\hhline{--~--~--}
 \multicolumn{2}{|c|}{$9$} &&\multicolumn{2}{|c|}{$42\frac{2} 
 {3}$}&&\multicolumn{2}{|c|}{$270$} \\ \hhline{--~--~--}
 \end{tabular}
 \end{center}

 \end{document}

Your \hhline s are empty in the p[1in}columns, so it looks normal, except for a missing vertical line in the first row. What did you expect? — Bernard, Dec 14 '18 at 19:09
@Bernhard, why is it missing in row 1 I thought I put that there and what syntax would I use to include in the p{1in} columns? — MathScholar, Dec 14 '18 at 19:12
The horizontal lines? Use \hhline{--------} or \hhline{*{8}{-}. — Bernard, Dec 14 '18 at 19:14
I am referring to the vertical line missing in the first box? The horizontal lines are okay — MathScholar, Dec 14 '18 at 19:17
It is not missing when I compile. Maybe a problem with the pdf viewer. What happens when you zoom? — Bernard, Dec 14 '18 at 19:19
@Yes I see when I zoom in. Maybe I should adjust the arraywidthrule ? Strange this is happening — MathScholar, Dec 14 '18 at 19:21
This is common and is viewer-dependent; not an issue with TeX and therefore off-topic. — Werner, Dec 14 '18 at 19:37
i clearly see all lines in sumatra as well in adobe DC recent version (screen resolution is 1920 x 1200). — Zarko, Dec 14 '18 at 19:38
I use SumatraPDF, which the recommended viewer (it doesn't lock the .pdf, and understands the .sync files, so you can do direct and inverse search). Also, don't you have holes in some vertical rules? — Bernard, Dec 14 '18 at 19:38

score 1 · Answer 1 · answered Jan 02 '20 at 03:30

Your lines are visible, but it depends on the PDF viewer you're using. Some viewers snap elements to a grid which could cause some components to be overridden by other things. This is commonly the case when adding colour to tables.

\documentclass{article}

\usepackage[table]{xcolor}
\usepackage{hhline}

\begin{document}

\begin{center}
  \renewcommand{\arraystretch}{1.2}%
  \begin{tabular}{ | c | p{1in} | c | p{1in} | c | }
    \hhline{-~-~-}
    \cellcolor{green!50!white}U.S. && \cellcolor{green!50!white}France && \cellcolor{green!50!white}Japan \\
    \hhline{-~-~-}
    $8$ && $41\frac{1}{3}$ && $260$ \\
    $9$ && $42\frac{2}{3}$ && $270$ \\
    \hhline{-~-~-}
  \end{tabular}
\end{center}

\end{document}

As you can see, there is no need for two columns in your setup, since a single column suffices.

score 0 · Answer 2 · answered Jan 02 '20 at 01:30

Taking into account the comments above and @Mico answer here-- https://tex.stackexchange.com/a/50355/197451-- added strut since the fractions were touching the horizontals

\documentclass{article}
\usepackage[table]{xcolor}
\usepackage{hhline}

\begin{document}
\newcommand\T{\rule{0pt}{2.6ex}}       % Top strut
\newcommand\B{\rule[-1.2ex]{0pt}{0pt}} % Bottom strut
 \begin{center}
 \begin{tabular}{|cc|p{1in}|cc|p{1in}|cc|} \hhline{--~--~--}
 \multicolumn{2}{|c|}
 {\cellcolor{green!50!white}U.S.} 
                                &&\multicolumn{2}{|c|} 
                                  {\cellcolor{green!50!white}France}
                                  \T\B
                                                                        &&\multicolumn{2}{|c|} 
                                                                          {\cellcolor{green!50!white}Japan} \\ \hhline{*{8}{-}}
\multicolumn{2}{|c|}
 {\cellcolor{blue!20!white}$8$} 
                                &&\multicolumn{2}{|c|}
                                  {\cellcolor{blue!20!white}$41
                                  \frac{1}{3}$} \T\B
                                                                        &&\multicolumn{2}{|c|} 
                                                                          {\cellcolor{blue!20!white}$260$} \\ 
                                                                          \hhline{*{8}{-}}
\multicolumn{2}{|c|}
 {\cellcolor{red!10!white}$9$} 
                                &&\multicolumn{2}{|c|}
                                  {\cellcolor{red!10!white}$42
                                  \frac{2}{3}$} \T\B
                                                                        &&\multicolumn{2}{|c|} 
                                                                          {\cellcolor{red!10!white}$270$} \\ 
                                                                          \hhline{*{8}{-}}                                                                          
 \end{tabular}
 \end{center}

score 0 · Accepted Answer · answered Jan 02 '20 at 03:42

It is not clear why you use define columns cor each sub-table and than in them multicolumn{2}{c}{...}. It should be sufficient to use just one ...
For better visibility of vertical rules in colored part of table you can increase thickness of rules. For example to 0.5pt.
For removing holes in vertical lines use for horizontal lines \hhline{|-|~|-|~|-|}
Vertical space around cells' contets can be increased by use of the cellspace package:

\documentclass{article}
\usepackage[table]{xcolor}
\usepackage{cellspace, hhline}
\setlength\cellspacetoplimit{2pt}
\setlength\cellspacebottomlimit{2pt}

\begin{document}
    \begin{center}
\setlength\arrayrulewidth{0.5pt}
\begin{tabular}{|Sc|p{1in}|Sc|p{1in}|Sc|}
    \hhline{|-|~|-|~|-|}
\cellcolor{green!50!white}{U.S.} 
    &&  \cellcolor{green!50!white}{France}  
        &&  \cellcolor{green!50!white}{Japan}   \\ 
    \hhline{|-|~|-|~|-|}
$8$ &&  $41\frac{1}{3}$ &&  $260$               \\ %\hhline{-~-~-}
$9$ &&  $42\frac{2}{3}$ &&  $270$               \\ 
    \hhline{|-|~|-|~|-|}
\end{tabular}
    \end{center}
\end{document}

score 0 · Answer 4 · answered Apr 02 '21 at 09:11

The environment {NiceTabular} of nicematrix has been created to address that problem. With this environment, the lines will not seem do disappear in some PDF viewers at some levels of zoom (and you will not see the thin white lines you see sometimes in some PDF viewers like SumatraPDF when you use colortbl or the key table of xcolor).

\documentclass{article}
\usepackage{nicematrix}
\begin{document}
\begin{center}
  \renewcommand{\arraystretch}{1.2}%
  \begin{NiceTabular}{|c|}[colortbl-like] \hline
    \cellcolor{green!50!white}U.S. \ \hline
    $8$ \
    $9$ \ \hline
  \end{NiceTabular}
  \hspace{1in}
  \begin{NiceTabular}{|c|}[colortbl-like] \hline
    \cellcolor{green!50!white}France \ \hline
    $41\frac{1}{3}$ \
    $42\frac{2}{3}$ \ \hline
  \end{NiceTabular}
  \hspace{1in}
  \begin{NiceTabular}{|c|}[colortbl-like] \hline
    \cellcolor{green!50!white}Japan \ \hline
    $260$ \
    $270$ \ \hline
  \end{NiceTabular}
\end{center}
\end{document}

You need several compilations (because nicematrix uses PGF/Tikz nodes under the hood).

Tables, Cellcolor and horizontal lines

4 Answers4