Comment 28 for bug 344814

Just to confirm, this is not in any way specific to the Chinese font mentioned; the same issue will appear with any font where the system only has a single weight, and the browser uses algorithmic "fake" bold.

For a simple example with Ubuntu 9.10, try

data:text/html,<p style="font-family:Furat;font-size:36pt;">hello world<br/><b>hello world</b></p>

Note that the Furat font (part of the Arabeyes collection, package ttf-arabeyes in Ubuntu) is only available in a single face. On screen and in Print Preview, the second line is clearly emboldened; but when printing to a PDF file, the glyphs are painted without the bold effect (but still with extra spacing).