If you look at the paragraph settings in Microsoft Word, there's an option for "Line spacing". This actually seems like a misnamed field, because it seems to control leading.
The default is
single, but there are options for
Exactly. If you use
exactly, you can approximate setting the leading value for lines (such as using
exactly 15pt to get 12/15pt Arial).
What does the default value of "single" actually mean? Is it scaling somehow to the font? Using some value built into the font?
The value of "single" line spacing is 1.15 or 115%. The page offers direction for changing the default value.