# Adjusting vertical space around equation using \empheq package

I have been using a simple method for adding a framed, colored box around important equations I want to highlight. The empheq package has worked well. However, I am having a lot of trouble figuring out the best way to add some vertical space around the frame.

Here is what I have done to create a new command called "myyellowonebox" -- the color is "myyellow1"

Preamble:

\definecolor{myyellow1}{RGB}{255, 255, 219}

\newcommand*\myyellowonebox[1]{%
\fcolorbox{myblue1}{myyellow1}{\hspace{2em}#1\hspace{2em}}}


And in the body, I have:

\begin{empheq}[box=\myyellowonebox]{equation}
y = \frac{1}{4p} x^2
\end{empheq}


This produces the following output:

However, I would like to add a larger gap above and below this equation. I was able to add horizontal padding using the \hspace in the argument of \framebox. But I can't seem to do the same for extra vertical space.

Any help would be greatly appreciated. I'd rather not use a fancy package, as this is about the sophistication I need for highlighting equations!

• Since you're using \fcolorbox, adjust \fboxsep: \setlength{\fboxsep}{<len>}... – Werner Feb 15 '17 at 19:25
• Thank you -- I tried that and it didn't seem to work. Perhaps I did not put the command in the correct place. Where would I insert the \setlength command as you suggested? – G. Khanna Feb 15 '17 at 19:54
• Add it in your preamble somewhere so it has the same effect across the whole document. – Werner Feb 15 '17 at 20:17
• Thank you -- that seemed to work. One last question -- is there a way to override this on an individual basis? – G. Khanna Feb 15 '17 at 20:28

\fcolorbox uses \fboxsep and \fboxrule as the widths of the separation and rule. So, adjusting that (globally) within the preamble would make for a consistent gap in your \myyellowonebox. You can adjust this locally as well and restore it as needed:

\documentclass{article}

\usepackage{xcolor,empheq}

\newcommand*\myyellowonebox[1]{\fcolorbox{blue!80}{yellow!15}{\hspace{2em}#1\hspace{2em}}}

\newlength{\fboxsave}\setlength{\fboxsave}{5pt}
\newcommand{\restorefboxsep}{\setlength{\fboxsep}{\fboxsave}}
\restorefboxsep% Default is 3.0pt

\begin{document}

\begin{empheq}[box=\myyellowonebox]{equation}
y = \frac{1}{4p} x^2
\end{empheq}

\setlength{\fboxsep}{10pt}% Update \fboxsep
\begin{empheq}[box=\myyellowonebox]{equation}
y = \frac{1}{4p} x^2
\end{empheq}
\restorefboxsep

\end{document}


The suggestion by Werner worked -- thank you! Here is the output I get when I add

\setlength{\fboxsep}{1em}


in the preamble. It looks like

Now just trying to figure out how I can override this if I need to on an individual basis.