# Set paragraph skip for each section

I am using the parskip package to remove indentation before each paragraph in my document. However, for certain sections of the document, I want to use the default paragraph indentation style (i.e. I want to disable parskip for that section only). Is there an easy way to do this?

If at all possible, I would like to be able to switch between using parskip and using indentfirst by section.

• \begingroup \parindent=<length> ... [text goes here] ... \endgroup (where <length> is something like, say, 18pt). – jon Mar 2 '17 at 4:09
• Could I make some sort of reusable "class" for indentation that I can just specify with a single tag at the start of each section? – pzp Mar 2 '17 at 4:11
• You can write \parindent=<length> [pretty much] anywhere you want and set it to 0pt or 1239pt or etc.; but if you want it for 'certain sections', then I'd use a group or define an environment (with \newenvironment. Since commands like \section don't naturally form groups, I think it is a bad idea to try to hook into them so things happen 'automatically'. Besides, using groups or environments helps keep your code comprehensible. – jon Mar 2 '17 at 4:16

Perhaps this is what you are looking for:

\documentclass[12pt]{article}
\usepackage{parskip, lipsum}
\makeatletter
\newcommand{\indentpars}[1][18pt]{%
% indentfirst.sty is the following two lines:
\let\@afterindentfalse\@afterindenttrue
\@afterindenttrue
% Now we set \parindent:
\parindent=#1\relax}
\makeatother

\begin{document}

\section{Default}
\lipsum

\section{Indent Pars}
\indentpars[3cm]
\lipsum

\section{Noindent Pars}
\parindent0pt

\lipsum

\begingroup % if doing this often, then an environment is the way to go
Indent pars again:
\indentpars[18pt]%
\lipsum[1-10]
\endgroup

\lipsum

\end{document}

• I'd be curious to learn why indenting and not-indenting paragraphs is needed. Non-indented paragraphs can confuse a reader, so mixing them with 'regular' paragraphs is probably ill-advised for most types of documents. – jon Mar 2 '17 at 4:27
• @pzp How do you separate non-indented paragraphs? If you use a blank line then consider the poor reader when a paragraph ends with a complete line and also ends the page, how is anyone able to tell that the first text on the next page is a new paragraph? – Peter Wilson Mar 2 '17 at 19:32