it is because we internally switched to rendering the font using WX widgets. It is simpler for us, and can be used on other platforms, such as mac. We can change the font
If I understand this correctly, it should be possible to use a font which does not need to be antialiased again and use (dabbler googling) wxGraphicsContext::SetAntialiasMode() with wxANTIALIAS_NONE. Then it could be nearly the same result as the previous stamp without losing portability?
If yes, then this is a vote for doing it like this. If not - well, then at least the size could maybe slightly increased?