does not work well yet!
The new primitive saveScreenVector works better.
command. Writes a file with the specified name, containing an Encapsulated Postscript (EPS) representation of the state of the graphics window. This file can be imported into other programs that understand EPS format. Restrictions: the drawing cannot use Arc, fill, PenErase, or PenReverse; any such instructions will be ignored in the translation to Postscript form.