XeLaTeX: Space between letters

Question

I use XeLaTeX. I need that words look stretched in some places in the document. How I can configure the space between letters in a word?

Answer 1

Based on example 44 from the fontspec documentation:

\documentclass{article}

\usepackage{fontspec}
    \usepackage{libertineotf}

\begin{document}
\addfontfeature{LetterSpace=0.0}
USE TRACKING FOR DISPLAY CAPS TEXT

\addfontfeature{LetterSpace=2.0}
USE TRACKING FOR DISPLAY CAPS TEXT
\end{document}

The documentation remarks:

This functionality should not be used for lowercase text, which is spacing correctly to begin with, but it can be very useful, in small amounts, when setting small caps or all caps titles. Also see the OpenType Uppercase option of the Letters feature

If you only want to apply the spacing to a few words, enclose it in a group:

normal {\addfontfeature{LetterSpace=2.0}spaced} normal

And you could put it in a macro, of course.