As of April 1994, there is no way to change font characteristics of virtual printers. In actuality, virtual printers send down HP PCL or PostScript code before each print job to configure the printer. You can add a couple of lines of PCL to your print queue configuration (on NOVELL, UNIX, VMS) to change the font size or pitch. This should make it transparent for anyone using the print queue since the code will be downloaded automatically before the actual job.
Here are the HP PCL commands to change font size and pitch:
<esc>(s#H : pitch selection (usually 10 or 16.66 built-in)
<esc>(s#V : character height (font size in points)
<esc> is the escape character
# is the actual value
For example, to change font size to 9 point:
<esc>(s9V
To enter <esc>, press the Ctrl-P keys followed by the Esc key.
Note: You must use an ASCII text editor like DOS EDIT. You cannot enter the <esc> character in some Windows-based editors like Notepad.