Variable white space between paragraphs

Question

I am having trouble finding out why the white space between my paragraphs is variable. Sorry, I am not allowed to post images but sometimes there is no white space (like it should be), just an indent to denote that a new paragraph has started. While sometimes the paragraphs start with an indent AND there is (sometimes substantial and thus variable) white space between the last sentence of the previous paragraph and the first sentence of the new paragraph.

In my tex file, there is no difference between what I do in the first and second examples of my text: just two hard returns to denote the start of a new paragraph. I was wondering whether it could be due to placement of figures and footnotes but I have no idea how to change it. I don't mind a little variable white space between paragraphs but the above example is too extreme for my taste. Thanks for your advice!

Answer 1

In general, spacing is variable in TeX, that is the reason why you use it.

First, make sure that you did not force latex to break lines or put objects in non-ideal positions. One possibility is using [H] specifier for floats as mentioned by egreg.

However, if there are extreme spacing you can modify the limits and the bahaviour of typesetting. You may use \raggedbottom if you want to move extra whitespaces to the bottom of the page instead of spreading it through the page. You may also change penalties and limits to let latex to break paragraphs and other items between pages and result in a more compact document. Check this page if you really want to squeeze spaces in Latex.

However, it is always better to post a minimum working example of your problem.

Answer 2

The placement of figures can influence this behaviour, but also the amount of text.

One word: glues. The following example will produce always a lot of space between paragraphs, filling two pages, but note that the paragraph skips is larger in the second page:

\documentclass{article}
\setlength{\parskip}{5em plus 1fil minus 5em}
\usepackage{lipsum}
\begin{document}
\lipsum[1-6]
\end{document}

If you print only five paragraphs (\lipsum[1-5]) will be
only minimal paragraph skips, so is fitted in only one page.

But if you print only two paragraphs (\lipsum[1-2]), they fill also only a page, but the skips is now huge.

That is, we have ordered to LaTeX that the paragraph skip should be usually 5em, but it can be shrunk/enlarged as needed to fit the remaining text in the actual page.

Using a reasonable range as 1em plus .1em minus 1.em, the stretch/shrink is hardly noticeable but could help a lot with the document layout.