By default, all of your typing is done in roman type. For emphasis or for captioning figures, etc., you may want different type styles. The possiblities are:
\textbf{quick brown fox} | bold face: quick brown fox |
\textit{quick brown fox} | italic: quick brown fox |
\textsf{quick brown fox} | sans serif: quick brown fox |
\textsl{quick brown fox} | slanted: quick brown fox |
\texttt{quick brown fox} | typewriter: quick brown fox |
\emph{quick brown fox} | emphasized: interchanges roman and italic |
\sc{quick brown fox} | small caps: QUICK brOWN FOX |
...Thus, we define a \emph{projective representation} to be...
which yields
...Thus, we define a projective representation to be...
{\textem...} declaration.
extends 
by including the
so-called New Font Selection Scheme (NFSS2) we have just illustrated.
The scheme greatly simplifies
the machinations necessary to effectively handle multiple typefaces in a
complex document under plain ``bare-bones'' .
The following table summarizes the various commands to switch among some
of the
more common typefaces available by default in :
| Effect | Local form | Global form |
| roman serif family | \textrm{...} | {\rmfamily...} |
| sans serif family | \textsf{...} | {\sffamily...} |
| typewriter family | \texttt{...} | {\ttfamily...} |
| bold face series | \textbf{...} | {\bfseries...} |
| medium face series | \textmd{...} | {\mdseries...} |
| upright shape | \textup{...} | {\upshape...} |
| italic shape | \textit{...} | {\itshape...} |
| slant shape | \textsl{...} | {\slshape...} |
| small CAPS shape | \textsc{...} | {\scshape...} |
| document font | \textnormal{...} | {\normalfont...} |
Font size can be modified using the ``local form'' \size{...} and the
``global form'' {\size...}, where size can be any of
\tiny | size | \normalsize
| size |
\scriptsize | size | \large
| size |
\footnotesize | size | \Large
| size |
\small | size | \LARGE
| size |
For special occasions, you can roll out the
\huge | size |
\Huge | size |
In case you're wondering, there is no \HUGE!