# Define font faces fallback with fontspec

If a font doesn't contain a specific face, it is substituted by default face (like \mdseries), while I want to define a chain of fallbacks, so LaTeX keeps searching for an existing face, until it succeeds, e. g. black -> extrabold -> bold -> regular.

How can I do that?

My MWE

\documentclass{article}

\usepackage{fontspec}

\newfontfamily{\Warnock}{WarnockPro}

\newfontfamily{\Vollkorn}{Vollkorn}[
FontFace        =   {black}{n}{*-Black},
]

\begin{document}

\fontseries{black}\selectfont
\Vollkorn Hello
\Warnock World

\end{document}