Double spacing using doublespacing environment

line-spacingparagraphssetspace

I want to locally apply double spacing in a certain paragraph of the document by using \begin{doublespacing} and \end{doublespacing} from the setspace package. However, I found it only takes effects if an extra blank line is added to the code, which is redundant for the code readability… Is there a better way/workaround to have double-spacing without the additional blank line?

MWE:

\documentclass[headsepline,footsepline,footinclude=false,twoside,fontsize=12pt,paper=a4,listof=totoc,bibliography=totoc,BCOR=12mm,DIV=12,chapterprefix=on,numbers=noenddot]{scrbook} % two-sided


\usepackage{setspace}
\usepackage{lipsum}


\begin{document}

\begin{doublespacing}
    \lipsum[1]
\end{doublespacing}

\begin{doublespacing}
    \lipsum[1]
                   % ---> Extra blank line necessary for the double-spacing
\end{doublespacing}

\end{document}

Best Answer

What you've discovered is not a bug but a core feature of the entire TeX paragraph builder system: The line-spacing within a paragraph depends on where the paragraph's end actually occurs. In the case of

\begin{doublespacing}
    \lipsum[1]
\end{doublespacing}

the end of the paragraph -- as far as TeX is concerned -- occurs not at the final period (aka full stop) of the lipsum filler text but after \end{doublespacing}. But by then the scope of the doublespacing environment has ended; hence, the text beloniging to lipsum[1] is (correctly, in my view) typeset single-spaced.

There are several ways to trigger the end of a paragraph:

  • One or more all-blank lines in the input. Incidentally, the line you present in the second code snippet of your posting is not all-blank (since it contains a comment) and therefore, contrary to your claim, does not suffice to make the paragraph double-spaced.

  • An explicit \par directive.

  • Implicit paragraph break instructions, issued by commands such as \chapter, \section, \begin{theorem}, and many more. Aside: the \\ ("double backslash") instruction induces a line break but not a paragraph break according to TeX's lexical rules.

Your main question was,

Is there a better way/workaround to have double-spacing without the additional blank line?

I'd say that issuing an explicit \par directive is your main alternative to leaving an all-blank line.

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