Enum Duplex
        Namespace TallComponents.PDF.Printing
    
The duplex setting print dialog is displayed.
Fields
Simplex
                Print single-sided.
            DuplexFlipShortEdge
                Duplex and flip on the short edge of the sheet.
            DuplexFlipLongEdge
                Duplex and flip on the long edge of the sheet.
            Unspecified
                Do not specify a duplex setting. 
            
            It appears that the presence of this setting has unwanted side effects. E.g. if Duplex is set
            to Simplex, checking the 'print on both sides' option in the print dialog of the Adobe PDF reader
            is ignored. By setting Duplex to 'Unspecified', the corresponding entry will be absent in the 
            viewer preferences dictionary.