Font size of small caps

Small caps `\textsc{}` seem to use:

• uppercase letters from the font with the default font size for typed uppercase letters,
• uppercase letters from the font with a smaller font size for typed lowercase letters.

How can I adjust the latter font size?

`\textsc` does not select two fonts it just selects one, however it is a font in which lowercase letters use the shapes usually assigned to uppercase. The relative heights as always for the relative heights of upper and lower case vary from font to font but are the choice of the font designer not something to set from TeX.
• @root actually I was thinking of unicode-math, see the examples of `range=` here tex.stackexchange.com/questions/420302/… but that's probably not helpful if you want this for text use. – David Carlisle Sep 19 '19 at 10:14
• (Note to myself: `range=` is described in the documentation of the `unicode-math` package.) – root Sep 19 '19 at 14:10
• @root only if you want to mark up every word with a font change `{\large A}{BC}` but that is a very poor approximation to small caps (you can however of course do that without making any extra definitions at all) – David Carlisle Sep 20 '19 at 17:40