When to use bold, italics, small caps, typewriter etc.?

Question

I'm a little confused on the purposes of each kind of text in LaTeX. I know the function of some of them, but sometimes people use each for different reasons. For example:

• \texttt is for code (no discussion right?).

• \emph is to make emphasis.

• \textsc is used for names, right?

• \textbf when should I use it?

• \textmd When should I use it?

And something more: If I write for example "HI-TECH C PIC Compiler" in between a paragraph, the capital words doesn't look very good. Is it convenient to use \textsf?

Can normal text be mixed with different types? Under which circumstances?

P.S: I'm using the article class with the normal font.

Answer 1

I think you are confusing visual markup with semantic markup.

\emph is semantic markup: it indicates that you want to emphasize some text, without specifying how that will affect the appearance of the text. The default is to make it italic, or for nested emph-within-emph to make it roman again. However, the default can be overridden if you later decide to use bold for emphasis: \renewcommand\emph{\textbf}.

\texttt, \textmd, \textsc and so on are visual markup. You should use them for implementing semantic markup. So, for example if you want to use the French convention of using small caps for family names, you could write \newcommand\familyname{\textsc} and have This was studied by John \familyname{Smith} and \familyname{Yao} Ming. If you then later decided that you no longer like this convention it is easy to change, in the preamble without needing to search through your text. Similarly you may want to write \newcommand\code{\texttt}

The visual \textXX commands will change 3 axes of the text: shape, family and weight.

• The shape axis covers: \textup, \textit, \textsc and \textsl
• The family axis covers: \textrm, \textsf, \texttt
• The weight axis covers: \textbf, \textmd
• Some fonts provide other options along these axes, or even as with MinionPro, completely new axes. (This functionality is now available independent of MinionPro in the fontaxes package, so that it can be used with other fonts.)

You can combine options from the different axes (some combinations, such as \textbf{\textt{...}} are not available by default, discussed here). For example:

• \newcommand\keyword[1]{\textsf{\textbf{#1}}}
• \newcommand\important[1]{\textbf{\textit{#1}}}

Regarding "HI-TECH C PIC Compiler": Some fonts (especially ones aimed at newspaper and magazine publishing) have a size of capitals that is intermediate between small-caps (\textsc) and full capitals, for exactly this purpose. The default tex computer modern fonts do not have this possibility, but the computer modern \textsc is not a true small-caps, being a little taller than the x-height of the font, so can be used this way: \newcommand\hitechcomp{\textsc{hi-tech c pic} compiler}

Answer 2

(I have no "right" answer, only some typographical hints.)

Most fonts can be categorized as either serif, sans serif or monospaced:

• Serif fonts (\textrm) are regularly used for the main text body. (Serifs are the small bars at the end of letter strokes that establish a visual base for text lines.)

• Sans serif fonts (\textsf) are often used for headings, tables and table/figure captions. (Typesetting the text body in sans serif is often frowned upon because of reasons of legibility.)

• Monospaced ("typewriter") fonts (\texttt) are mostly limited to code listings and URL's.

For every font category or "family", the following attributes (and combinations of attributes) are possible, although often not available in practice:

• Medium is the "normal" (upright, non-bold) font. (The commands \textup resp. \textmd are used to cancel the effects of other attribute commands and switch back to a medium font - see Lev Bishop's answer for details.)

• Italic (\textit) can be used to emphasize parts of the text without making those parts "stick out" at first glance. (\emph defaults to \textit.) Italic fonts are also suited for low-hierarchy headings. Italics are a separate font design - not only are the letters slanted, but many of them (e.g. "a", "g") have distinct forms.

• Slanted (\textsl) is a surrogate font in case no "real" italic font is around.

• Bold (\textbf) is suited for (top) headings. In the text body, a bold font should be used only if you really want some words to "stick out" - e.g. keywords in a dictionary.

• Small caps (\textsc) are another possibility for emphasis. They are sometimes used for names, but are especially suited for acronyms (UNESCO, PIC Compiler) where capital letters would disrupt the text image. "Real" small caps are a separate font design - don't use "faked" small caps (downscaled capital letters).

Answer 3

This is a matter of typographic style. There are no definitive rules.

You should consult a style guide to see what is conventionally done. The Elements of Typographic Style and The Chicago Manual of Style are both worth the read.