# How to use double line in LyX tables

I want to have double lines in the top row in my tables in lyx. I searched through the site but could not find how to do this.

• There are several possible solutions. Could we have a minimal code? – Bernard Nov 13 '14 at 20:42
• I do not think LyX support for tables is intuitive in many cases. And I say this as one of the authors of the tabular code in LyX. I would like to redesign the code someday. I would appreciate it if you made a feature request for double lines in LyX at lyx.org/trac – scottkosty Nov 13 '14 at 23:29

Due to the nature of the setup in LyX, you could insert a ERT with \hline in the first cell of the table:
It is advisable to use the "Formal" table border setting instead (Edit > Table Settings... > Borders > Style > Formal), since it uses booktabs in the presentation. This package uses \toprule and \bottomrule to emphasize the top/bottom of the table, setting it with a thicker rule.
To get a double border for both top and bottom, we can use the "Formal" table border setting as mentioned by Werner, then add the following in the preamble to convert the top and bottom borders to double \hline:
\renewcommand\toprule{\hline\hline}