I would like to economize my blank papers so I print with this command according to the enscript man page: enscript -r -2 --margins=4
The option explained as following :
--margins=left:right:top:bottom
Adjust page marginals to be exact left, right, top and bottom
PostScript points. Any of arguments can be left empty in which
case the default value is used.

but the printout's margins dit not get smaller. And there are some escape character that is replaced by octal number, enscript can not handle UTF-8.

I understand nothing about duplex, seeing the prospect of losing a lot of toner and paper, I am so afraid to try it with enscript. Being coward, I normally use the -a option to print 0dd pages firstand then return the printed pages to print the even pages. It is so robot.

Could you tell me your experience with enscript and duplex printing ?

For the margins command you still need the colons : even if no argument is given. So

--margins=4:::

will change the left margin to 4 points, leaving others at default. Works for me.

I think duplex printing depends entirely on the capabilities of the printer and the settings in the printer driver. Enscript knows nothing about this. It just assembles the pages in the order you specify.

You can always print to file (-p file.ps) and look at the output with ghostscript to save toner if you are experimenting.

Don't know what you can do about non ASCII characters if the -X option does not work. The HOWTO

http://www.tldp.org/HOWTO/Unicode-HOWTO-5.html

has some alternatives to enscript.