from Learn about Type at Monotype Imaging Inc.


Hart’s Rules for Compositors and Readers at the University Press Oxford states “Unless instructions are given to the contrary, capitals, small capitals, numerals, and punctuation in displayed lines should be letter-spaced.” The lines above, in Sabon Initial cap & small cap, show the difference — which non-designers among you may consider pretty minor. I might argue with the third line and want even more space between the two Ts, but I do think the overall color of the two sets of lines shows how beneficial letter-spacing caps and small caps can be. That cap W in the second line really sticks out, but your letter-spacing can’t do too much about that.

Caps extend from the base line (a few typefaces have one or two descend below) up to the top of the ascenders. Small caps are designed to be the same height as the x-height of the face.

Hart’s Rules calls for small caps (which I cannot generate in this blog’s typeface) to be used for abbreviations like AD, AM, BC, and tells us that they should be set without letter spacing in these instances.

Quaintly they command “Text references to capital symbols in plates and line-blocks to be in small caps, except in scientific work, where capitals are used.” It is true that (to me at least) small caps tend to have a humanistic, as opposed to scientific, look — no doubt because that’s where one tends to meet them. In scientific setting symbols have so much significance that using a small cap for aesthetic reasons runs the risk of having readers stopping to ponder if there’s some meaningful distinction being made between upper case C and small cap C. For analogous reasons one will be unlikely to meet old style figures in scientific or mathematical setting.

Cambridge practice, as codified by Judith Butcher in her Copy-editing, is perhaps best just directly quoted:

Use of small capitals

Small capitals are often used for AD, BC, except with lining figures where small capitals would look too small: AD 1990. [I cannot make my AD small, so the point is lost. These are lining figures though.] In the USA they are used for a.m. and p.m. Small capitals are also used for quoted words originally in capitals and for most capitalized roman numbers, e.g. vol. XII [again I can go smaller], though full capitals are always used in titles such as Henry VII and for LXX (Septuagint). Some authors type lower-case roman numbers to indicate small capitals rather than full capitals; ask the author if you are not sure what is required.

I love typography has a detailed examination of small caps, demonstrating that small caps are not just scaled-down caps, but separately designed characters. If you are one of those who think the letter-spacing in the example at the top is not discernible or irrelevant, you might probably think it a waste of time to design small caps separately when you could just scale down the caps. But the whole typesetting craft, bearing 5½ centuries of trial and error, knows what’s right.