cairo-ft-font uses FT_GlyphSlot_Embolden to do synthetic bold. Bug 490475 comment 5 makes me suspect that the emboldened glyph outlines are not embedded.
There are two fonts embedded, one for each of regular and bold weights
but AFAIK the two fonts might be the same. I don't know whether there is any way to tell the PS/PDF interpreter to embolden one of these by any particular amount suitable to match the metrics from FT_GlyphSlot_Embolden.
The backend used on NT uses GDI to do synthetic bold, so I suspect the same issue may exist there. (If it doesn't then maybe that provides some clues on how to fix this for the FreeType backend.)
cairo-ft-font uses FT_GlyphSlot_ Embolden to do synthetic bold.
Bug 490475 comment 5 makes me suspect that the emboldened glyph outlines are not embedded.
There are two fonts embedded, one for each of regular and bold weights
/f-0-0 1 Tf -1<030304050406 >-1<0307> ]TJ 02>-84< 03>-84< 03>-83< 04>-83< 05>-84< 06>-84< 04>-83< 07>-84< 03>-84< 08>]TJ
[<0102>
/f-1-0 1 Tf
0 -1.694444 Td
[<01>-83<
but AFAIK the two fonts might be the same. I don't know whether there is any way to tell the PS/PDF interpreter to embolden one of these by any particular amount suitable to match the metrics from FT_GlyphSlot_ Embolden.
The backend used on NT uses GDI to do synthetic bold, so I suspect the same issue may exist there. (If it doesn't then maybe that provides some clues on how to fix this for the FreeType backend.)