How can I get letter spacing?

Question

Letter spacing is a special kind of emphasis often used in combination with blackletter fonts. A letter spaced has 0.125 em spaces between its characters, but some ligatures are preserved. For example: »B ä ck e r ſt r a ß e« How can I get letter spacing with (La)TeX?

Answer 1

With the microtype package and pdfTeX, you just need to enclose the text which you want to emphasize in a \textls command. You can adjust the amount of letterspacing (Sperrsatz) globally by adding letterspace=125 to the package options or, alternatively, locally by providing it as an optional argument to the \textls command (in multiples of 1/1000 em).

\documentclass{article}

\usepackage{yfonts}
\usepackage[letterspace=125]{microtype}

\begin{document}
\frakfamily
\textls{B\"ackerstra\ss e}
\textls[50]{B\"ackerstra\ss e}
\end{document}

If you are not interested in the other features of microtype such as margin kerning, you can instead load the letterspace package with the same option.

Answer 2

This page from the UniFraktur project goes into detail about letterspacing and shows what to do for XeLaTeX.

Answer 3

You can use the soulutf8 package and its \sodef command to define a new command to get the desired letter spacing; to mantain a ligature you can use \mbox inside the argument of the newly defined command:

\documentclass{article} 
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage{soulutf8}

\sodef\Sp{}{.125em}{1em plus1em}{2em plus.1em minus.1em}


\begin{document}
\Sp{Bäcker\mbox{ßt}raße}
\end{document}

Answer 4

LuaLaTeX solution.

\documentclass{article}
\usepackage{fontspec}
\newfontfamily\letterspaced{Latin Modern Roman}[LetterSpace=50]
\begin{document}
Hello world

{\letterspaced Hello world}

Hello world
\end{document}

Output:

---

There's an alternative solution that does not require defining a font family, but it's much slower.

\documentclass{article}
\usepackage{fontspec}
\begin{document}
\fontspec{Latin Modern Roman}  % set the default font https://tex.stackexchange.com/q/643918/250119

Hello world fi

{
\addfontfeature{LetterSpace=50}
Hello world fi
}

{
\addfontfeature{LetterSpace=50,Ligatures={NoCommon, NoDiscretionary}}  % https://tex.stackexchange.com/a/103242/250119
Hello world fi
}

Hello world fi

\end{document}

Output:

• First line is normal text,
• second line is LetterSpace,
• third line is LetterSpace with ligatures disabled,
• forth line is back to normal text.

How much slower?

I compare two documents with the following changes:

\csname prg_replicate:nn\endcsname{200}{
{\letterspaced Hello world}

}

versus

\csname prg_replicate:nn\endcsname{200}{
{\addfontfeature{LetterSpace=50} Hello world}

}

The time taken are 0m4.137s and 0m1.254s respectively. So that evaluates to 14ms per usage, or: for every 70 usages of \addfontfeature, your compilation time slows down by a second.