[Samba] force duplex printing

[Eric PEYREMORTE]

Hi all,

I use samba + cups. I would like to force duplex printing on some of my 
printers. I didn't find a solution on the client side.
Is there any solution on the server side ?
I saw the following example in smb.conf man ://|
cups options|/ = |"raw,media=a4,job-sheets=secret,secret"|/
Could i do the same and add duplex=duplexnotumble ???

The smb.conf example seems strange to me as raw means "send as received 
by the client", so how would it be possible to as option such as media=a4 ?

Eric PEYREMORTE