I think it's probably unnecessary to think of changing the length of skips between paragraphs in the sense that the standard spacing of one skip defined by the parskip package is always fine. But what about if I wanted two skips instead of one, or even worse if I wanted to change the length of the skip. I was thinking about modifying the value of \parskip, which apparently solves the problem. Truth is it also modifies my enumerate environments and I don't want that. Actually that makes me think that it may probably do the same thing with some other environments. How can I solve this?
[Tex/LaTex] How to change separation space between paragraphs
parskip
Related Solutions
I found a copy of the relevant class file here; assuming that this is the same as the one that you are using, the culprit is the following comment:
\parskip 0pt % Extra vertical space between paragraphs.
% Set to 0pt outside sections, to keep section heads
% uniformly spaced. The value of parskip is set
% to leading value _within_ sections.
% 12 Jan 2000 gkmt
Sure enough, looking further down in the document we find that in the definition of the section commands, \parskip gets reset. For example:
\def\@ssect#1#2#3#4#5{%
\@tempskipa #3\relax
\ifdim \@tempskipa>\z@
\begingroup
#4{%
\@hangfrom{\hskip #1}%
\interlinepenalty \@M #5\@@par}%
\endgroup
\else
\def\@svsechd{#4{\hskip #1\relax #5}}%
\fi
\vskip -10.5pt %gkmt, 7 jan 00 -- had been -14pt, now set to parskip
\@xsect{#3}\parskip=10.5pt} % within the starred section, parskip = leading 12 Jan 2000 gkmt
That innocuous \parskip=10.5pt at the end means that every time a \section, \subsection, \subsubsection, or \paragraph command is used then \parskip gets reset to 10.5pt. (The command \@sect has the same ending.)
So to reduce \parskip, you need to reduce it each time that you start a section or otherwise. Depending on your needs, a variety of strategies are possible. The simplest would be to have a copy of the class file in the same directory as the TeX file and simply edit out that extra \parskip=10.5pt (actually, edit out both of them: one from \@ssect and one from \@sect). If you need to leave the class file pristine for some reason, then you can redefine these commands in your preamble. The simplest would be to simply copy out the definitions from the class file with the appropriate modifications to \parskip. If you do this, then the copied definitions need to be sandwiched between \makeatletter ... \makeatother.
If you want to be a bit more fancy, you could have the \section commands remember what \parskip is when they are called, then reset it at the end. This would involve hacking three commands from the class file, since the command \@startsection also messes with \parskip. So it would be something like (not tested!):
\makeatletter
\let\orig@startsection=\@startsection
\let\orig@ssect=\@ssect
\let\orig@sect=\@sect
\newskip\orig@parskip
\orig@parskip\parskip % just for safety's sake!
\def\@startsection{%
\orig@parskip\parskip%
\orig@startsection}
\def\@ssect#1#2#3#4#5{%
\orig@ssect{#1}{#2}{#3}{#4}{#5}%
\parskip\orig@parskip}
\def\@sect#1#2#3#4#5#6[#7]#8{%
\orig@sect{#1}{#2}{#3}{#4}{#5}{#6}[#7]{#8}%
\parskip\orig@parskip}
\makeatother
Just load the parskip package and don't change the \parskip and \parindent lengths manually. In the document body, don't use \parskip but a blank line to separate paragraphs.
BTW, there's normally no need to add manual line breaks (\\) in the text.
\documentclass{article}
\usepackage{parskip}
\begin{document}
We explain in this section how to obtain headings
for the various sections and subsections of our
document.
In the ``article'' style, the document may be divided up
into sections, subsections and subsubsections, and each
can be given a title, printed in a boldface font,
simply by issuing the appropriate command.
\end{document}
Best Answer
Apart from the "dont' do this" warning that you will most certainly receive, the
memoirclass allows you to change the regular\parskipvalue without messing up other things, by providing an\abnormalparskipmacro: