default to duplex printing

screenless/bureau/bureau.py

@@ -341,7 +341,7 @@ class Bureau(object):
         self.log.debug("rendering with: " + self.html2pdf + htmlpath + " " + pdfpath)
         subprocess.call(self.html2pdf + htmlpath + " " + pdfpath +
                         " A4 1920px", shell=True)
-        subprocess.call("lpr " + pdfpath, shell=True)
+        subprocess.call("lpr -o sides=two-sided-long-edge -o InputSlot=Upper " + pdfpath, shell=True)
 
     # TODO: make this asynchronous
     def print_small(self, text, cut=True):