# Let fontspec handle bold font automatically

I recently installed a commercial font called Monospace 821. The font came in ttf format and I installed it as usual in a Linux machine.

Problem is that when I use

\textbf{Bold}


the resulting text is not printed in bold. To get the bold I'm using the following workaround:

\newfontfamily\mybold{Monospace821BTBold}
\newcommand{\mytextbf}[1]{\mybold #1}


My question is: is this normal or is there a way to get the bold font automatically when using \textbf{...}?

\documentclass{article}
\usepackage{fontspec}
\setmainfont{Latin Modern Roman}
\newfontfamily\monobt{Monospace821BT}
\newfontfamily\mybold{Monospace821BTBold}
\newcommand{\mytextbf}[1]{\mybold #1}
\begin{document}

{\monobt \textbf{this is not bold}}

\mytextbf{this is bold}
\end{document}


The monospaced font is not used as tt font, I have another font set to \setmonofont{...} so I can't put Monospace 821 there.

If fontspec is unable to find the bold font associated to a medium series font, uou can use the normal options also with \newfontfamily:

\newfontfamily{\monobt}{Monospace821BT}[
BoldFont={Monospace821BTBold}
]


and then

{\monobt\textbf{This is bold}}


should work.

Notice that the options should go before the font name with older versions of fontspec.