Some time go I had a problem with bulk printing labels from Microsoft Word on ZDesigner S4M. As I know problem concerns many others printers .
Problem: Printed labels are rotated -90 degrees. Changing paper orientation in MS Word or rotating paper settings in printer drivers does not help.
Solution: Let system use driver’s settings while printed, instead application’s settings. It will require to configure label size directly via driver, so in my situation it was label 7.5×3.4 mm on roll with gaps 3mm.
Printer properties select Printer Settings TAB, Always use driver settings (Ignore apps default settings) at bottom
After changing settings, labels printed via mail merge in MS Word were printed correctly. Before printing is good to print only first page, to make additional correction before sending all to printer. I had to change darkness because printer default settings were replaced by driver.