VBA to turn duplex printing on or off from Access
If your printer supports duplex printing, this VBA code will turn off or on duplex printing from within an Access database.
To turn duplex printing on:
Dim prt As Printer
Set prt = Application.Printer
With prt
.Duplex = acPRDPVertical
End With
To turn duplex printing off:
Dim prt As Printer
Set prt = Application.Printer
With prt
.Duplex = acPRDPSimplex
End With