% Copyright 2007 by Till Tantau
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% This file may be distributed and/or modified
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% 2. under the GNU Free Documentation License.
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% $Header: /cvsroot/latex-beamer/latex-beamer/doc/beamerug-fonts.tex,v 1.13 2007/01/28 20:48:21 tantau Exp $

\section{Fonts}

\label{section-fonts}

The first subsection introduces the predefined font
themes that come with \beamer\ and which make it easy to change the
fonts used in a presentation. The next subsection describes further
special commands for changing some basic attributes of the fonts used in a 
presentation. The last subsection explains how you can get a much more
fine-grained control over the fonts used for every individual element
of a presentation. 





\subsection{Font Themes}

\beamer\ comes with a set of font themes. When you use such a theme,
certain fonts are changed as described below. You can use several font
themes in concert. For historical reasons, you cannot change all
aspects of the fonts used using font themes---in same cases special
commands and options are needed, which are described in the next
subsection.

The following font themes only change certain font attributes, they do
not choose special font families (although that would also be possible
and themes doing just that might be added in the future). Currently,
to change the font family, you need to load special packages as
explained in the next subsection.


\begin{fontthemeexample}{default}
  The default font theme installs a sans serif font for all text of
  the presentation. The default theme installs different font sizes
  for things like titles or head- and footlines, but does not use
  boldface or italics for ``hilighting.'' To change some or all text
  to a serif font, use the |serif| theme.

  Note: The command |\mathrm| will always produce upright (not
  slanted), serif text and the command |\mathsf| will always produce
  upright, sans-serif text. The command |\mathbf| will produce
  upright, bold-face, sans-serif or serif text, depending on whether
  |mathsans| or |mathserif| is used.

  To produce an upright, sans-serif or serif text, depending on
  whether |mathsans| or |mathserif| is used, you can use for instance
  the command |\operatorname| from the |amsmath| package. Using this
  command instead of |\mathrm| or |\mathsf| directly will
  automatically adjust  upright mathematical text if you switch from
  sans-serif to serif or back.
\end{fontthemeexample}

\begin{fontthemeexample*}{professionalfonts}
  This font theme does not really change any fonts. Rather, it
  \emph{suppresses} certain internal replacements performed by
  \beamer. If you use ``professional fonts'' (fonts that you buy and
  that come with a complete set of every symbol in all modes), you do
  not want \beamer\ to meddle with the fonts you use.  \beamer\
  normally replaces certain character glyphs in mathematical text by
  more appropriate versions. For example, \beamer\ will normally
  replace glyphs such that the italic characters from the main font
  are used for variables in mathematical text. If your professional
  font package takes care of this already, \beamer's meddling should
  be switched off. Note that \beamer's substitution is automatically
  turned off if one of the following packages is loaded: |mathtime|,
  |mathpmnt|, |lucidabr|, |mtpro|, and |hvmath|. If your favorite
  professional font package is not among these, use the
  |professionalfont| option (and write me an email, so that the
  package can be added). 
\end{fontthemeexample*}



\begin{fontthemeexample}[\oarg{options}]{serif}
  This theme causes all text to be typeset using the default serif font
  (except if you specify certain \meta{options}). You might wish to
  consult Section~\ref{section-guidelines-serif} on whether you should
  use serif fonts.

  The following \meta{options} may be given:
  \begin{itemize}
  \item
    \declare{|stillsansserifmath|}
    causes mathematical text still to be typeset using sans
    serif. This option only makes sense if you also use the
    |stillsansseriftext| option since sans serif math inside serif
    text look silly. 
  \item
    \declare{|stillsansserifsmall|}
    will cause ``small'' text to be still typeset using sans
    serif. This refers to the text in the headline, footline, and
    sidebars.  Using this options is often advisable since small text
    is often easier to read in sans serif.
  \item
    \declare{|stillsansseriflarge|}
    will cause ``large'' text like the presentation title or the frame
    title to be still typeset using sans serif. Sans serif titles with
    serif text are a popular combination in typography.
  \item
    \declare{|stillsansseriftext|}
    will cause normal text (none of the above three) to be still
    typeset using sans serif. If you use this option, you should most
    likely also use the first two. However, by not using
    |stillsansseriflarge|, you get a serif (possibly italic) title
    over a sans serif text. This can be an interesting visual
    effect. Naturally, ``interesting typographic effect'' can mean
    ``terrible typographic effect'' if you choose the wrong fonts
    combinations or sizes. You'll need some typographic experience to
    judge this correctly. If in doubt, try asking someone who should
    now. 
  \item
    \declare{|onlymath|}
    is a short-cut for selecting all of the above options except for
    the first. Thus, using this option causes only mathematical text
    to by typeset using a serif font. Recall that, by default,
    mathematical formulas are also typeset using sans-serif
    letters. In most cases, this is visually the most pleasing and
    easily readable way of typesetting mathematical formulas if the
    surrounding text is typeset using sans serif. However,
    in mathematical texts the font used to render, say, a variable is
    sometimes used to differentiate between different meanings of this
    variable. In such case, it may be necessary to typeset
    mathematical text using serif letters. Also, if you have a lot of
    mathematical text, the audience may be quicker to ``parse'' it if
    it is typeset the way people usually read mathematical text: in a
    serif font. 
  \end{itemize}
\end{fontthemeexample}



\begin{fontthemeexample}[\oarg{options}]{structurebold}
  This font theme will cause titles and text in the headlines,
  footlines, and sidebars to be typeset in a bold font.

  The following \meta{options} may be given:
  \begin{itemize}
  \item
    \declare{|onlysmall|}
    will cause only ``small'' text to be typeset in bold. More
    precisely, only the text in the headline, footline, and sidebars
    is changed to be typeset in bold. Large titles are not affected.
  \item
    \declare{|onlylarge|}
    will cause only ``large'' text to be typeset in bold. These are
    the main title, frame titles, and section entries in the table of
    contents.     
  \end{itemize}

  As pointed out in Section~\ref{section-sizes}, you should use this
  theme (possibly with the |onlysmall| option) if your font is not
  scaled down properly or for light-on-dark text.

  The normal themes do not install this theme by default, while the
  old compatibility themes do. Since you can reload the theme once it
  has been loaded, you cannot use this theme with the old
  compatibility themes to set also titles to a bold font. 
\end{fontthemeexample}

\begin{fontthemeexample}[\oarg{options}]{structureitalicserif}
  This theme is similarly as the |structurebold| font theme, but where
  |structurebold| makes text bold, this theme typesets it in italics and
  in the standard serif font. The same \meta{options} as for the
  |structurebold| theme are supported. See
  Section~\ref{section-italics} for the pros and cons 
  of using italics.  
\end{fontthemeexample}

\begin{fontthemeexample}[\oarg{options}]{structuresmallcapsserif}
  Again, this theme does exactly the same as the |structurebold| font theme,
  only this time text is set using small caps and a serif
    font. The same \meta{options} as for the |structurebold| theme are
  supported. See Section~\ref{section-smallcaps} for the pros and cons
  of using small caps.  
\end{fontthemeexample}






\subsection{Font Changes Made Without Using Font Themes} 

While most font decisions can be made using font themes, for
historical reasons some changes can only be made using class
options or by loading special packages. These options are explained in
the following. Possibly, these options will be replaced by themes in
the future.


\subsubsection{Choosing a Font Size for Normal Text}

As pointed out in Section~\ref{section-sizes}, measuring the default
font size in points is not really a good idea for
presentations. Nevertheless, \beamer\ does just that, setting the
default font size to 11pt as usual. This may seem ridiculously small, but 
the actual size of each frame is just 128mm times 96mm and the viewer
application enlarges the font. By specifying a default font size
smaller than 11pt you can put more onto each slide, by specifying a
larger font size you can fit on less.

To specify the font size, you can use the following class options:

\begin{classoption}{8pt}
  This is way too small. Requires that the package |extsize|
  is installed.
\end{classoption}

\begin{classoption}{9pt}
  This is also too small. Requires that the package |extsize|
  is installed.
\end{classoption}

\begin{classoption}{10pt}
  If you really need to fit much onto each frame, use this
  option. Works without |extsize|.
\end{classoption}

\begin{classoption}{smaller}
  Same as the |10pt| option.
\end{classoption}

\begin{classoption}{11pt}
  The default font size. You need not specify this option.
\end{classoption}

\begin{classoption}{12pt}
  Makes all fonts a little bigger, which makes the text more
  readable. The downside is that less fits onto each frame.
\end{classoption}

\begin{classoption}{bigger}
  Same as the |12pt| option.
\end{classoption}

\begin{classoption}{14pt}
  Makes all fonts somewhat bigger. Requires |extsize| to be installed.
\end{classoption}

\begin{classoption}{17pt}
  This is about the default size of PowerPoint. Requires |extsize| to
  be installed. 
\end{classoption}

\begin{classoption}{20pt}
  This is really huge. Requires |extsize| to be installed.
\end{classoption}



\subsubsection{Choosing a Font Family}

\label{section-substition}

By default, \beamer\ uses the Computer Modern fonts. To change this,
you can use one of the prepared packages of \LaTeX's font
mechanism. For example, to change to Times/Helvetica, simply add 
\begin{verbatim}
\usepackage{mathptmx}
\usepackage{helvet}
\end{verbatim}
in your preamble. Note that if you do not use the |serif| font theme,
Helvetica (not Times) will be selected as the text font.

There may be many other fonts available on your
installation. Typically, at least some of the following packages
should be available: |avant|, |bookman|, |chancery|, |charter|,
|euler|, |helvet|, |mathtime|, |mathptm|, |mathptmx|, |newcent|,
|palatino|, |pifont|, |utopia|.


\subsubsection{Choosing a Font Encodings}
\label{section-font-encoding}

The same font can come in different encodings, which are (very roughly
spoken) the ways the characters of a text are mapped to glyphs (the
actual shape of a particular character in a particular font at a
particular size). In \TeX\ two encodings are often used with Latin
characters: the T1~encoding and the OT1~encoding (old T1~encoding).

Conceptually, the newer T1~encoding is preferable over the old
OT1~encoding. For example, hyphenation of words containing umlauts
(like the famous German word Fr\"aulein) will work only if you use the
T1~encoding. Unfortunately, the EC fonts, that is, the T1-encoded
Computer Modern fonts, are distributed on small installations just as
MetaFont sources and only have bitmap renditions of each glyph. For
this reason, using the T1-encoded EC fonts on such small installations
will produce \pdf\ files that render poorly.

MiK\TeX\ (for Windows platforms) and \texttt{teTeX} for
\textsc{unix}\slash Linux can be installed with different levels of 
completeness. Concerning the Computer Modern fonts, the following
packages can be installed: |cm-super| fonts, |lmodern| (Latin Modern)
fonts, and |lgc| fonts, the latter containing the Latin, Greek, and
Cyrillic alphabets. Concerning other fonts,  the |txfonts| and
|pxfonts| are two extended sets of the Times and the Palatino
PostScript fonts, both packages containing extended sets of
mathematical glyphs. Most other standard PostScript fonts are also
available in T1~encoding.

Among the packages that make available the Computer Modern fonts in the
T1~encoding, the package |lmodern| may be suggested. If you use
|lmodern|, several extra fonts become available (like a sans-serif
boldface math) and extra symbols (like proper guillemots).

To select the T1 encoding, use \verb|\usepackage[T1]{fontenc}|. Thus, if you
have the LM~fonts installed, you could write
\begin{verbatim}
\usepackage{lmodern}
\usepackage[T1]{fontenc}
\end{verbatim}
to get beautiful outline fonts and correct hyphenation. Note, however, that
certain older versions of the LM~bundle did not include correct glyphs
for ligatures like ``fi,'' which may cause trouble. Double check
that all ligatures are displayed correctly and, if not, update.




\subsection{Changing the Fonts Used for Different Elements of a Presentation}

This section explains how \beamer's font management works.

\subsubsection{Overview of Beamer's Font Management}

\beamer's font mechanism is somewhat similar to \beamer's color
mechanism, but not quite the same. As for colors, every \beamer\
element, like the frame titles, the document title, the footnotes, and
so on has a certain \beamer-font. As for colors, on the one hand you
can specify the font of each element individually; on the other hand
fonts also use inheritance, thereby making it easy to globally change
the fonts used for, say, ``titlelike things'' or for ``itemizelike
things.''

While a \beamer-color has a certain foreground and a certain
background, either of which may be empty, a \beamer-font has a size, a
shape, a series, and a family, each of which may be empty. The
inheritance relation among \beamer-fonts is not necessarily the same
as between \beamer-colors, though I have tried to match them whenever
possible. 

Multiple inheritance plays a more important rule for
fonts than it does for colors. A font might inherit the attributes of
two different fonts. If one of them specifies that the font should be,
say, boldface and the other specifies that the font should be, say,
large, then the child font will be both large and bold. 

As for fonts, the description of the font used for an element is given
after the description of the element. 


\subsubsection{Using Beamer's Fonts}

To use a \beamer-font, you can use the command
|\usebeamerfont|. Inside the templates for elements, this command will
(typically) have already been called for you, so you will only
seldomly have to use this command. 

\begin{command}{\usebeamerfont\opt{|*|}\marg{beamer-font name}}
  This command changes the current font to the font specified by the
  \meta{beamer-font name}. The \meta{beamer-font name} can be a
  not-too-fancyful text and may contain spaces. Typical examples are
  |frametitle| or |section in toc| or |My Font 1|. \beamer-fonts can
  have (and should) have the same name as \beamer-templates and
  \beamer-colors.

  \example |\usebeamerfont{frametitle}|

  In the unstarred version of this command, the font is changed
  according to the attributes specified in the \meta{beamer-font
  name}, but unspecified attributes remain unchanged. For example, if
  the font specifies that the font should be ``bold,'' but specifies
  nothing else, and if the current font is large, then
  |\usebeamerfont| causes the the current font to become large and
  bold.

  In the starred version of this command, the font is first reset
  before the font's attributes are applied. Thus, in the above example
  of a \beamer-font having only the attribute ``boldface'' set, saying
  |\usebeamerfont*| will \emph{always} cause the current font to
  become a normal-size, normal-shape, bold, default-family font.
\end{command}


\subsubsection{Setting Beamer's Fonts}

As for \beamer-colors, there exists a central command for setting and
changing \beamer-fonts.

\begin{command}{\setbeamerfont\opt{|*|}\marg{beamer-font
      name}\marg{attributes}}
  This command sets or resets certain attributes of the \beamer-font
  \meta{beamer-font name}. In the unstarred version, this command just
  adds those attributes that have not been mentioned in a previous
  call and overwrites those that have been mentioned. Thus, the
  following two command blocks have the same effect:

  \example
\begin{verbatim}
\setbeamerfont{frametitle}{size=\large}
\setbeamerfont{frametitle}{series=\bfseries}

\setbeamerfont{frametitle}{size=\large,series=\bfseries}
\end{verbatim}

  In the starred version, the font attributes are first completely
  reset, that is, set to be empty.

  The following \meta{attributes} may be given:
  \begin{itemize}
  \item \declare{|size=|\meta{size command}} sets the size
    attribute of the \beamer font. The \meta{size command} should be a
    normal \LaTeX-command used for setting the font size or it should
    be empty. Useful commands include |\tiny|, |\scriptsize|,
    |\footnotesize|, |\small|, |\normalsize|, |\large|, |\Large|,
    |\huge|, and |\Huge|. \beamer\ also introduces the two font sizes
    |\Tiny| and |\TINY| for \emph{really} small text. But you should
    know \emph{exactly} what you are doing if you use them. You have
    been warned.

    Note that there is a different between
    specifying and empty command and specifying |\normalsize|: Making
    the size attribute ``empty'' means that the font size should not
    be changed when this font is used, while specifying |\normalsize|
    means that the size should be set to the normal size whenever this
    font is used.
  \item \declare{|size*=|\marg{size in pt}\marg{baselineskip}} sets
    the size attribute of   the font to the given \meta{size in pt}
    and the baseline skip to the given value. Note that, depending on
    what  kind of font you use, not  all font sizes may be
    available. Also,  certain font sizes are much less desirable than
    other ones; the standard commands take care of choosing
    appropriate sizes for you. Do not use this options unless you have
    a good reason. This command has the same effect as
    |size={\fontsize|\marg{size in pt}\marg{baselineskip}|}|.  
  \item \declare{|shape=|\meta{shape command}} sets the shape
    attribute of the font. The command should be command like
    |\itshape|, |\slshape|, |\scshape|, or |\upshape|.
  \item \declare{|shape*=|\marg{shape attribute abbreviation}} sets
    the shape attribute of the font using the \LaTeX's abbreviations
    for attributes. This command has the same effect as
    |shape={\fontshape|\marg{shape attributes abbreviation}|}|.  
  \item \declare{|series=|\meta{series command}} sets the ``series''
    attribute of the font. The command should be command like
    |\bfseries|.
  \item \declare{|series*=|\marg{series attribute abbreviation}} has
    the same effect as |series={\fontseries|\marg{series attributes
        abbreviation}|}|.
  \item \declare{|family=|\meta{family command}} sets the font family
    attribute. The command should be a \LaTeX-font command like
    |\rmfamily| or |\sffamily|. 
  \item \declare{|family*=|\marg{family name}} sets the font family
    attribute to the given \meta{family name}. The command has the
    same effect as |family={\fontfamily|\marg{family name}|}|. The
    \meta{family name} is, normally, a somewhat cryptic abbreviation
    of a font family name that installed somewhere on the system. For
    example, the \meta{family name} for Times happens to be
    |ptm|. No one can remember these names, so its perfectly normal if
    you have to look them up laboriously.
  \item \declare{|parent=|\marg{parent list}} specifies a list of
    parent fonts. When the \beamer-font is used, the parents are used
    first. Thus, any font attributes set by one of the parents is
    inherited by the \beamer-font, except if this attribute is
    overwritten by the font.
  \end{itemize}

  \example
\begin{verbatim}
\setbeamerfont{parent A}{size=\large}
\setbeamerfont{parent B}{series=\bfseries}
\setbeamerfont{child}{parent={parent A, parent B},size=\small}

\normalfont
This text is in a normal font.
\usebeamerfont{parent A}
This text is large.
\usebeamerfont{parent B}
This text is large and bold.
\usebeamerfont{parent B}
This text is still large and bold.
\usebeamerfont*{parent B}
This text is only bold, but not large.
\usebeamerfont{child}
This text is small and bold.
\end{verbatim}
\end{command}




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