[texhax] line spacing

[Robin Fairbairns]

> I have a document with text in two different 
> sizes: 10pt and 12pt. It seems that by 
> default the line spacing between the two are 
> the same. I would like to make the space 
> between lines with text size 10pt to be 
> smaller than that of text size 12pt.

what may be confusing you is that you can only have one line spacing
in any given paragraph -- see
http://www.tex.ac.uk/cgi-bin/texfaq2html?label=paraparam
and read \linspread{...} for \raggedright in the examples

> I have done some experimenting with 
> \linespread{size} but this seems to only work 
> for the whole document. 

no, it works per paragraph, but you have to change font to pick it up.
until latex goes through the business of selecting a new font (i.e.,
something different from what's currently selected -- when it spots
you're asking for the "same font" it "knows" it's got nothing to do)
it just doesn't notice a change in linespread.

[this isn't terribly clever, but then linespread is a pretty
off-the-wall thing to do, anyway.  as you suggest, best done before
\begin{document} for the whole document; but there are ways of getting
changes right -- notably the code of setspace.sty]