French Characters do not print in SAPScript Form

I modified the MEDRUCK form for PO and inserted some new label texts. These texts contain characters like é and è.

When I do a Print Preview of the PO, the text shows fine.

However, when I print the PO, the characters on paper are replaced by a combination of 2 characters (like "|).

I suppose this has to do with the printer, but where should I make any modifications to get this right ?