# Is \\[<len>] as bad as \\ for new lines?

I have heard on multiple occasions that one should rather not use \\ to force new lines, unless one uses it in environments like tabular or align, and it is advised to use \par instead.

How about starting new lines and creating a given amound of vertical spacing with \\[<len>]? Is this macro derived from \\ and in the same way "bad" for normal text outside of environments? Should I use something like \par\vspace{<len>} instead? Or what is the cleanest, and most elegant way of creating lines of text with a fixed vertical spacing?

Thanks!

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It is just as bad to use \\[1em]. Use \par and set the parskip to a reasonable length (which would be something around \z@. Please see also [What are the differences between \par\vspace{2cm}\noindent and \\[2cm]?](What are the differences between \par\vspace{2cm}\noindent and \\[2cm]?) and When to use \par and when \\? – Johannes_B Aug 31 '14 at 18:20
\ is only "bad" because explicit line breaking and spacing is generally "bad" (or at least shouldn't be done in general documents) so \[..] and \par\vspace are equally bad – David Carlisle Aug 31 '14 at 19:24
the phrasing here isn't optimally clear. the double backslash is only bad if it is used instead of a paragraph break. if you're using it to break a line in order to start the next line with something in particular, for example a url that you want to highlight, that's entirely reasonable. – barbara beeton Aug 31 '14 at 21:07
@barbarabeeton I'd use a display for the url (you definitely want more indentation). For technical writing an unnumbered list with a single entry is also perfectly acceptable. – Marc van Dongen Sep 1 '14 at 13:47
@MarcvanDongen -- good points. what i was trying to say (not very well, i guess) is that it's okay to use a double backslash to end a line if something other than a new paragraph, a blank line, or a display comes next. possibly better example: breaking the lines of a poem or an address. – barbara beeton Sep 1 '14 at 15:41

For one-off spacing changes, \smallskip, \medskip, and \bigskip are defined for this task.

\documentclass{article}

\newcommand\TestSkip[1]{%
\begin{minipage}[t]{0.2\linewidth}
\raggedright
This is some dummy text.

#1

This is some dummy text.
\end{minipage}}
\begin{document}
\TestSkip{}
\TestSkip{\smallskip}
\TestSkip{\medskip}
\TestSkip{\bigskip}
\end{document}


After rereading the question, I'll note that these aren't 'fixed' spaces; they're rubber lengths (defined according to \smallskipamount, etc.) and will shrink/expand according to the amount of available vertical space when the page is being built.

\$ texdef smallskip smallskipamount medskipamount bigskipamount

\smallskip:
macro:->\vskip \smallskipamount

\smallskipamount:
\skip13

\the\smallskipamount:
3.0pt plus 1.0pt minus 1.0pt

\medskipamount:
\skip14

\the\medskipamount:
6.0pt plus 2.0pt minus 2.0pt

\bigskipamount:
\skip15

\the\bigskipamount:
12.0pt plus 4.0pt minus 4.0pt

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