Font weight documentation is a bit confusing

[roperzh]

• How to use bold and normal modifiers? seems like they do not belong in the Base section.

[luizbills]

just follow the docs: http://tachyons.io/docs/typography/font-weight/

.b for bold (700)
.normal to force normal font-weight (default 400)
and .fw{1...9} to choose an exact font-weight value