use PostScript::Simple;
    
# create a new PostScript object
$p = new PostScript::Simple(papersize => "A4",
                            colour => 1,
                            eps => 0,
                            units => "in");
    
# create a new page
$p->newpage;

#select a shade of grey
$p->setcolour("grey20");

 # draw a filled square with lower left point at (20,20)
$p->polygon( {offset => [10,10], filled => 1},
             10,10, 10,20, 20,20, 20,10, 10,10);

$p->output("file.ps");