Full capitals are much more effective and are to be preferred where the words are few.

Small capitals of 12 or 14 point body are distinct but smaller sizes are crowded and hard to read.

This difficulty can sometimes be remedied by hair spacing.

Over spacing of such lines is objectionable though it has sometimes prevailed as a temporary fashion.
Small capitals used in running titles are exposed to heavy wear and their shallow counters are liable to get choked up with ink.

Capitals of the monotint or of a light-faced antique are sometimes selected for books frequently reprinted where the wear on the exposed running titles is very severe.
In reprinting letters it is common to use small capitals for the name of the place from which the letter was written, for the name of the addressee, and for the signature.