Should we set FONT in % or em?

[toplisek]

I like to know benefits of setting fonts and sizes with small { font-size:85%; }
or small { font-size:0.50em; }

What is the best consistent way in updated coded CSS?
If we had em in the past I could make larger fonts using em...
Printed page will be recognised by font-size : 12pt;

[BeeDeeDubbleU]

There was a discussion about this last week.

See [webmasterworld.com...]