This article explains how to duplex print using PDFRasterizer.NET 3.0.
Duplex printing
Duplex printing is achieved by telling the printer driver to send send duplex instructions to the printer as demonstrated by the following code snippet.
PrintDocument printDocument = new PrintDocument();
printDocument.PrinterSettings.Duplex = Duplex.Vertical;
1 PrintDocument printDocument = new PrintDocument();
2 printDocument.PrinterSettings.Duplex = Duplex.Vertical;