More files!
diff --git a/postscript/prologues/duplex.ps b/postscript/prologues/duplex.ps
new file mode 100644
index 0000000..99397cb
--- /dev/null
+++ b/postscript/prologues/duplex.ps
@@ -0,0 +1,4 @@
+%!PS-Adobe-3.0
+statusdict /setduplexmode known {
+	statusdict begin true setduplexmode end
+} if