Set the text pitch.
void pdfSetTextFixedPitch(double pitch)
This function sets the horizontal character pitch, in points. This value is used in line printer mode, physical layout mode, and table layout mode; it will be ignored in other modes.
If the pitch is set to zero (the default value), line printer mode will automatically compute the pitch. Physical layout and table layout modes will not used a fixed pitch.
This setting is global - it applies to all PDF handles.