Printing without ShowDialog gives blank pages
Try doing a Measure, Arrange, and UpdateLayout right before the printvisual, like this:
DV.Measure(new System.Windows.Size(PD.PrintableAreaWidth, PD.PrintableAreaHeight));DV.Arrange(new System.Windows.Rect(new System.Windows.Point(0, 0), DV.DesiredSize));DV.UpdateLayout();PD.PrintVisual(DV, "TEST");