Argthtjtr

I need make the border of a table table thicker, as in the following image:

How can I do this?

My code is:

documentclass{article}

    usepackage[table]{xcolor}



    begin{document}

    begingroup

    defarraystretch{2.2}%

    begin{tabular}{|p{25mm}|c|c|c|}

      hline

       multicolumn{4}{|c|}{aaaaa} \ % <===============================

      hline

      rowcolor{cyan}

      1 & 1e-1 & 1e-2 & 1e-2 \

      hline

      2 & 1e-1 & 1e-2 & 1e-2 \

      hline

      3 & 1e-1 & 1e-2 & 1e-2 \

      hline

      4 & 1e-1 & 1e-2 & 1e-2 \

      hline

      5 & 1e-1 & 1e-2 & 1e-2 \

      hline

    end{tabular}

    endgroup

    end{document}

If I've well understood what you want, it's easy with boldline:

documentclass{article}

usepackage[table]{xcolor}

usepackage{boldline} 



begin{document}



begingroup

defarraystretch{2.2}%

begin{tabular}{V{4}p{25mm}|c|c|cV{4}}

  hlineB{4}

   multicolumn{4}{V{4}cV{4}}{aaaaa} \ % <===============================

  hline

  rowcolor{cyan}

  1 & 1e-1 & 1e-2 & 1e-2 \

  hline

  2 & 1e-1 & 1e-2 & 1e-2 \

  hline

  3 & 1e-1 & 1e-2 & 1e-2 \

  hline

  4 & 1e-1 & 1e-2 & 1e-2 \

  hline

  5 & 1e-1 & 1e-2 & 1e-2 \

  hlineB{3}

end{tabular}

endgroup



end{document} 

One option is to insert the table into a tikz node with thick borders.

documentclass{article}

usepackage[table]{xcolor}

usepackage{tikz}



begin{document}



begin{tikzpicture}

    renewcommandarraystretch{2.2}%

    node[draw,ultra thick,inner sep=.4pt]{begin{tabular}{|p{25mm}|c|c|c|}

      hline

       multicolumn{4}{|c|}{aaaaa} \ % <===============================

      hline

      rowcolor{cyan}

      1 & 1e-1 & 1e-2 & 1e-2 \

      hline

      2 & 1e-1 & 1e-2 & 1e-2 \

      hline

      3 & 1e-1 & 1e-2 & 1e-2 \

      hline

      4 & 1e-1 & 1e-2 & 1e-2 \

      hline

      5 & 1e-1 & 1e-2 & 1e-2 \

      hline

    end{tabular}};

end{tikzpicture}



end{document}

You can place the entire tabular inside an fbox:

documentclass{article}



usepackage[table]{xcolor}

usepackage{booktabs}



begin{document}



begingroup

renewcommandarraystretch{2.2}%

setlength{fboxsep}{0pt}%

setlength{fboxrule}{2.6pt}%

fbox{%

  begin{tabular}{|p{25mm}|c|c|c|}

    hline

    multicolumn{4}{|c|}{aaaaa} \

    hline

    rowcolor{cyan}

    1 & 1e-1 & 1e-2 & 1e-2 \

    hline

    2 & 1e-1 & 1e-2 & 1e-2 \

    hline

    3 & 1e-1 & 1e-2 & 1e-2 \

    hline

    4 & 1e-1 & 1e-2 & 1e-2 \

    hline

    5 & 1e-1 & 1e-2 & 1e-2 \

    hline

  end{tabular}%

}

endgroup



bigskip



begin{tabular}{ p{25mm} *{3}{c} }

  toprule

  multicolumn{4}{c}{aaaaa} \

  midrule

  rowcolor{cyan}%

  1 & 1e-1 & 1e-2 & 1e-2 \

  2 & 1e-1 & 1e-2 & 1e-2 \

  3 & 1e-1 & 1e-2 & 1e-2 \

  4 & 1e-1 & 1e-2 & 1e-2 \

  5 & 1e-1 & 1e-2 & 1e-2 \

  bottomrule

end{tabular}



end{document}

I'd be more inclined to use booktabs to set the table: