duplex print not working on hp6520 using libreoffice writer on linux mint 17.1

[Fanciatune]

Please can you help solve the duplex problem?
The printer driver is hplip.
The software is up to date as per the Linux Mint 17.1 updater.
Libreoffice 4.2.8.2.
Driver test page prints duplex correctly.
Media is A4 autoduplex.

[mariosv]

Please take a look to this threads:

Libreoffice 4.1 Printer settings don't stay selected

The related bug is fdo#67449 (opened by OP?) It may be possible to work around the issue by using the printer administration utility /opt/libreoffice4.1/program/spadmin to permanently set the required option.

How do I get Libre Office Writer to duplex print?

I have an HP Officejet Pro 8600 which supports double sided printing. It duplexes fine with AbiWord but I can’t seem to get Libre Office Writer to do it. In the print window under Properties/device I have selected that the duplexer is installed and under Properties/paper I have specified “Duplex: Long edge.” Also, when I initially set up the printer I specified that the duplexer attachment was installed. On the main print window there is no place where I can make any other selections in rega…

[GustavoPinsard]

Please try selecting PostScript (Level from driver) in the Properties → Device tab of your printer. The default value is “Automatic: PDF”, which can cause problems with several printers.

I was able to confirm this workd because I couldn’t duplex print on my HD OfficeJet 8600 from LibreOffice, but all other programs worked fined. Changing to PostScript solved the problem.