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