# Top and bottom margin with longtable

Is it possible to define a top and bottom margin for all longtable in the entire document? My current solution works, but it forces me to repeat code every time I use longtable. I would like to add a distance for the top and the bottom of 3em.

\vspace{3em}
\begin{longtable}{…}
…
\end{longtable}
\vspace{3em}

• \setlenth\LTpre{3em} \setlength\LTpost{3em} but note these are not top and bottom margin they won't affect spaces at a page break. – David Carlisle Sep 16 '18 at 14:43
• @DavidCarlisle you're missing a g there. Should be \setlength\LTpre{3em}. – Skillmon Sep 16 '18 at 14:46
• @Skillmon oops, yes;-) – David Carlisle Sep 16 '18 at 14:49
• @DavidCarlisle Thanks David! Precisely what I was looking for. – Socrates Sep 16 '18 at 15:00

\setlength\LTpre{3em} \setlength\LTpost{3em} will set the length before and after the long table. (This isn't really a mrgin setting, it is space added in the page body, before and after the table, not above and below each page of a multi-page table.)