Some typographers say it's a good habit to increase the letterspace when writing words in caps or small caps. So my question is, how to do it with pdflatex and/or xelatex? And while we're at it, which words would you alter this way? Acronyms like USA, NATO, IBM, GNU, etc.? How about words like PCs, UdSSR, FreeBSD or TV-Station?
[Tex/LaTex] Increasing Letterspace for words in caps or small caps
microtypesmall-capsspacing
Related Solutions
All things being equal, you're probably using Computer Modern Roman, not because iopart has loaded it, but because it's the default used if you don't explicitly specify any other. (Your pdf reader can confirm this for you. Usually all you need do is open the document then, depending on the reader, looking in Properties / Fonts. Look for fontnames like 'CMR10' (CM 10pt roman) and 'CMCSC10' (CM 10pt small caps).)
There are many solutions to your problem. Apart from explicitly rescaling your lining figures as Niel points out (tho take care that 'faking' small caps doesn't run you into, say, untoward kerning issues), two of the easiest are these:
If you wish to stay with computer modern, use
\oldstylenumsto convert normal "lining" (uppercase) figures to "oldstyle" ("text" or lowercase) figures. E.g.,\textsc{fp}\oldstylenums{6}. Note, however, that some CMR oldstyle figures look less like osf than you might want (the digit '6' happens to be one of these).Alternatively, you might prefer the look and feel of the oldstyle figures offered by different fonts. However, not every font offers these natively (i.e., you might need to apply the
\oldstylenumscommand when using most other non-CMR fonts).
Here's some code that might help to check out many of the rather few fonts that open up text figures. Assuming each font is actually loaded on your system, one by one just uncomment and recomment each of the commented lines below, compiling each to see which look and feel you most prefer. Note, however, that this technique typesets all figures in your document in oldstyle. Nevertheless, it means you won't need to apply the \oldstylenums command at any time.
\documentclass{article}
\usepackage[T1]{fontenc}
%\usepackage[sc,osf]{mathpazo} % Palatino with pazo math fonts
%\renewcommand*\rmdefault{pplx} % Palatino with lining (uppercase) nums
%\renewcommand*\rmdefault{pplj} % Palatino with text (lowercase or oldstyle) nums
%\usepackage[osf]{venturis}
%\usepackage[osf]{libertine}
%\usepackage[osf]{MinionPro}
%\usepackage[fulloldstylenums]{kpfonts}
\begin{document}
\textsc{fp9876543210}
9876543210
\end{document}
Not really a compelling rationale, but I would go with method 2 because that's what The Economist does:
(The Economist, November 6th 2010)
Best Answer
Use the microtype package, loading it with
[tracking=smallcaps]should take care of small capsFor all-uppercase words you can use microtype's
\textls, e.g.(I came across this here, check the provided “Präambel”, the spacing/scaling might be font specific, so use with care and check your output, maybe someone else could comment on this one)
hope this helps