Defining Custom Font Environments And Commands In Latex
Setting the Main Document Font
The main font used in a LaTeX document can be set by declaring the font family in the documentclass declaration at the start of the file. Common font families used in LaTeX include Times, Helvetica, Palatino, among others. The font family can be explicitly chosen by passing the family option such as:
\documentclass[12pt, oneside, a4paper, sans]{report}
This would set the sans serif Helvetica font as the default document font at 12 point size. The font size can also be adjusted as needed.
Creating New Font Commands
New commands for quickly switching between different fonts can be created by using LaTeX's \newcommand declaration. For example:
\newcommand{\code}[1]{\fontfamily{pcr}\selectfont #1}
This defines a new command \code{} which can be used to switch to a monospace font for displaying code. It would be used as \code{sample code}. Multiple font commands can be daisy chained to apply complex formatting.
Font Packages and Availability
LaTeX comes bundled with a set of basic fonts, but many more advanced fonts can be used by importing external packages. Popular packages like mathpax provide additional math fonts. The luximono package provides quality monospace/typewriter fonts. Before using a font package, check if it is available on your LaTeX distribution using the package manager.
Many fonts are available to download as well if not initally included. LaTeX font catalogues like FontSquirrel offer hundreds of fonts that can be manually installed if needed.
Changing Font Sizes
Font sizes can be adjusted using commands like \tiny, \scriptsize, \small, \normalsize, \large, \Large, \huge and \Huge. Each steps up to progressively larger sizes. More granular control over exact font size values is possible using:
{\fontsize{10pt}{12pt}\selectfont text}
This would set the font size to 10pt with a line height of 12pt. The scope after \selectfont applies the size change. Custom size commands can also be defined using \newcommand as before.
Bold, Italic, and Other Font Styles
In addition to size, the font weight and style can be modified:
\begin{itemize}
\item \textbf{Bold text}
\item \textit{Italic text}
\item \textsl{Slanted text}
\item \textsf{Sans serif font}
\item \texttt{Monospaced font}
\item \textsc{Small caps text}
\item \textmd{Medium weight text}
\item \textup{Upright text}
\end{itemize}
Combined declarations like \textbf{\Large text} are possible for bold large text. Custom commands like \newcommand{\kw}[1]{\textbf{#1}} can simplify usage.
Font Colors and Backgrounds
Font colors can be changed using the color package and commands like \color{blue}:
\usepackage{color}
{\color{blue} blue text}
Other color model types like RGB or CMYK can be specified with \color[rgb]{0,0,1}. Custom colors can be defined using \definecolor.
Text background colors can be set using \colorbox{background}{text}:
\colorbox{yellow}{highlighted text}
This would highlight the text in a yellow box. Custom commands like \newcommand{\highlight}[1]{\colorbox{yellow}{#1}} simplify reuse.
Importing External Fonts
Fonts not bundled with LaTeX can be imported from external sources using the \usepackage directive along with the font or graphics packages:
\usepackage[T1]{fontenc}
\usepackage{graphicx}
\usepackage[default,scale=MatchLowercase]{source-sans-pro}
This would import the Source Sans Pro font for document-wide usage. The style and scale parameters adjust the font display properties accordingly. Similar approaches work for other external font libraries and packages.
Troubleshooting Font Issues
If fonts specified in LaTeX source files do not render correctly in the compiled output, common issues include:
- Missing font packages or libraries - Install needed packages
- Incompatible font encodings - Stick to encodings like OT1 and T1
- Conflicting font package options - Remove clashing options
- Deprecated LaTeX font commands - Update to modern usage
- Restricted TeX engines - Use engines like XeLaTeX or LuaLaTeX for more font support
Font rendering issues can also indicate missing fonts on your operating system. Consult LaTeX compiler logs and warnings for diagnostic clues.
Example Code for Defining Font Environments
Below shows an example stylesheet containing custom font commands and environments for reusing formatting configurations:
\usepackage[T1]{fontenc}
\newcommand{\code}[1]{\fontfamily{pcr}\selectfont{\color{darkgray}#1}}
\newenvironment{important}
{\fontfamily{phv}\selectfont\large\bfseries\color{blue}}
{\par}
\begin{document}
The \code{main()} method prints \textit{Hello World}:
\begin{important}
This is important text
\end{important}
\end{document}
The above defines reusable commands for monospaced code (\code) and highlighted importance (\begin{important} \end{important}). Font styles are stacked and scoped within the declarations for quick formatting without disrupting document flow.
