I know that there was a discussion on this list a while back, but I'd
love to get a more recent update as to what people feel is the best
'standard' font size for an average audience. We are currently in
a bit of a debate with a client about their 'standard' font size.
Their guidelines dictate using 14px Arial / 13px Verdana for content,
which we feel is too large. We feel that a 12px Arial / 11px Verdana
standard is more reasonable to most users (in essence, using the 75%
base font adjustment from the browser standards and then using ems
from that point forward).
I've done some research of different usability sites and found that
MOST agree that a standard of 75%/0.8em/12px seem to be the best
size, but it is by no means unanimous. But I trust the opinions here
to help me prove my point or theirs.
P.S. We do use font-sizers on all of our sites, and they run at
settings of 1.0/1.2/1.5em (effectively 12px, 14px, 18px), which I
think takes care of the normal gamut of needs; in my opinion, most
users who need a font size larger than that already know how to get
it and don't need us to intervene.