My solution to this problem was to download the PPD driver from
http://linuxprinting.org/show_printe...um=Lexmark-Z12 Then I went to the Print Manager and choose Add Printer which started the CUPS printing wizard....
I choose local printer
I choose the printer port (USB01)
I was then prompted to select the make and model, but I clicked on "other" which allowed me to install the PPD driver manual, which loaded properly.
I click Test to print a test page, which was perfect in black - I didn't test in colour.
I contined the wizard until completion.
Pleae note that this driver has not been tested in colour as per stated on the download page. Similarly, I have only got it working in KDE. Hope this helps other Lexmark Z12 owners like me.