The following code does not set the printer to duplex but is does change color mode to B&W
DoCmd.OpenReport Report_Name, acViewDesign, , , acHidden
With Reports(Report_Name).Printer
.Orientation = acPRORPortrait
.ColorMode = acPRCMMonochrome
.Duplex = acPRDPHorizontal
End With
DoCmd.OpenReport Report_Name, acViewPreview
I also tried vbViewPreview in the first OpenReport
and I have tried this on 2 different PCs and printers - both printers support duplex