Originally Posted by alex_d
Doing this is turning out suprisingly difficult since a font's boldness is actually an inherent property.
Actually its pretty simple but there are two issues that generally make it a b ad idea:
1. If the font is embedded it likely didn't come with the PDF (most embedded fonts come in Roman only)
2. The width of glyphs in bold fonts are generally larger than the width of the roman glyphs. The PDF will very probably come out looking like it was typeset by random chance.