On Tue, 20 May 2014, David Carlisle wrote:

    [...]

    If you want \mathbf{Var}  to "look OK" then you need to kern the V and a
    and that means (as far as I understand the current situation) either using a
    text bold font or having tables somewhere in the macro layer and inserting
    kerns "by hand",  that is: make the macros iterate over every character
    inserting
    kerns where needed. (but maybe luatex and or xetex can modify the font
    metrics
    at font loading time?

i think maybe the "proper" thing
to do is recommend declaring these
multi-letter non-\mathrm strings
as a special kind of operator name.
may require a new command ...

i agree with david that the text
kerning is definitely wanted here.
					-- bb