# Effect of changing \fontfamily and \familydefault

Assume I would like to change the font for a section of text, e.g. use Bookman for both headings and paragraphs (similarly to the explanations in this community wiki guide).

If I change the \familydefault, as in section (1), only headings are affected. If on the other hand I select Bookman as the \fontfamily, it affects only paragraph text but not headings (2). Combining both commands gives the desired result (3), as does adding a \normalfont command to \familydefault* (4).

What causes this behaviour? Does \fontfamily set some "currentfont" variable which is not accessed when headings are formatted? And why does changing \familydefault immediately affect headings, but not text?

*This was pointed out in a comment by @mpg.

\documentclass{article}
\usepackage[T1]{fontenc}

%print a _short section of lipsum text
\newcommand{\shlipsum}{%
\section{A quick brown fox}
Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Ut purus elit, vestibulum ut, placerat ac, adipiscing vitae, felis. Curabitur dictum gravida mauris. Nam arcu libero, nonummy eget, consectetuer id, vulputate a, magna.\\%
}

%reset font to typewriter CM

\begin{document}

\resetfont
\shlipsum

\resetfont
\fontfamily{pbk}\selectfont         %sets paragraph text only
\shlipsum

\resetfont
\renewcommand{\familydefault}{pbk}
\fontfamily{pbk}\selectfont
\shlipsum

\resetfont
\renewcommand{\familydefault}{pbk}
\normalfont
\shlipsum

\end{document}
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