How to Change Line Spacing in a Shortstack-Like Box

The standard \shortstack is convenient for putting centered lines in a small box, but it offers limited control over the distance between those lines. A one-column tabular gives you more control while still producing a compact box that can sit in running text.

For general text, make the box with \begin{tabular}{c}...\end{tabular}. To adjust the spacing without affecting other tables, change \arraystretch inside a group around that tabular.

A reusable shortstack-like command

This command accepts an optional spacing factor. Its default, 1, uses the usual tabular row spacing; a larger value increases the row height, and a smaller value decreases it.

\documentclass{article}

\newcommand{\flexshortstack}[2][1]{%
  \begingroup
  \renewcommand{\arraystretch}{#1}%
  \begin{tabular}[c]{@{}c@{}}#2\end{tabular}%
  \endgroup
}

\begin{document}

Default spacing: \flexshortstack{First line\\Second line}.

More spacing: \flexshortstack[1.5]{First line\\Second line}.

A specific extra gap:
\begin{tabular}[c]{@{}c@{}}
  First line\\[4pt]
  Second line
\end{tabular}.

\end{document}

The optional [c] on tabular vertically centers the box with respect to the surrounding baseline. The c in the column specification centers the text horizontally, matching the default horizontal alignment of \shortstack. The @{}...@{} removes the tabular’s usual left and right padding, so the result is a close fit around the text. The group keeps the \arraystretch change local to this box.

Choose a spacing method

Use \arraystretch when you want to scale the spacing throughout the stack. For example, \flexshortstack[1.5]{A\\B\\C} makes the rows taller than the default. It is a scaling factor, not a measurement in points, and it changes the row heights rather than specifying an exact baseline-to-baseline distance.

If you want to add a fixed amount at just one break, use the optional length on the tabular row break: \\[4pt] adds 4 points after that row. This is useful when only one pair of lines needs extra separation.

Using the box in math mode

tabular is a text-mode environment. If the stacked material belongs inside a mathematical expression, use array instead. For example:

\[
  \renewcommand{\arraystretch}{1.4}
  \begin{array}{c}
    x+y\\
    z+w
  \end{array}
\]

For a reusable math-mode command, define a similar wrapper around array and keep the \arraystretch change local. Do not place a tabular directly inside math mode; use array or wrap text content in \text{...} when appropriate.

Common mistakes

• Changing \arraystretch globally: A redefinition outside a group can affect later tables. Keep it inside braces or a group when the change is only for one box.
• Treating the factor as a point value: \arraystretch scales row spacing; it does not mean “add this many points.” Use the row-break length for a specific fixed gap.
• Using the wrong environment: tabular is for text mode, while array is for math mode.
• Expecting identical dimensions to \shortstack: The contents and alignment can match closely, but tabular row struts and spacing rules differ. Adjust the factor to suit the surrounding text.