If you want to print on paper the view displayed in ViewportLayout control, you can follow the approach reported in this article.

Suppose that your viewport looks like this:

and you want to print it on paper in hidden line mode.

Your printButton handler should contain the following code lines:

private void printButton_Click(object sender, EventArgs e)
{
   //Save current view Camera
   cameraSaved = (Camera)viewportLayout1.Camera.Clone();

   viewportLayout1.Camera.ProjectionMode = projectionType.Orthographic;

   //Creates printing setting object and customize it
   HiddenLinesViewSettings hdlS = new HiddenLinesViewSettings(viewportLayout1);
   hdlS.PenEdge.Color = Color.Blue;
   hdlS.PenSilhouette.Color = Color.Blue;
   hdlS.PenEdge.Width = 1f;
   hdlS.PenSilhouette.Width = 1f;

   //Creates paper preview
   HiddenLinesViewOnPaperPreview hdl = new HiddenLinesViewOnPaperPreview(hdlS, new Size(800, 600), 0.25);
   viewportLayout1.StartWork(hdl);

   //Restore saved view
   viewportLayout1.RestoreView(cameraSaved);
} 

Private Sub printButton_Click(sender As Object, e As EventArgs)
    'Save current view
    Dim cameraSaved As Camera = DirectCast(ViewportLayout1.Camera.Clone(), Camera)

    ViewportLayout1.Camera.ProjectionMode = projectionType.Orthographic

    'Creates printing setting object and customize it
    Dim hdlS As New HiddenLinesViewSettings(viewportLayout1)
    hdlS.PenEdge.Color = Color.Blue
    hdlS.PenSilhouette.Color = Color.Blue
    hdlS.PenEdge.Width = 1F
    hdlS.PenSilhouette.Width = 1F

    'Creates paper preview
    Dim hdl As New HiddenLinesViewOnPaperPreview(hdlS, New Size(800, 600), 0.25)
    ViewportLayout1.StartWork(hdl)

    'Restore saved view
    ViewportLayout1.RestoreView(cameraSaved)
End Sub

Through HiddenLinesViewSetting class you can customize several preview parameters (here you can see PenEdge and PenSilhouette color set to Blue, and their width line thickness set to one).

Finally, object HiddenLinesViewOnPaperPreview creates the preview opening the window reported below.

Please note that HiddenLinesViewOnPaperPreview class takes as arguments the settings we have created first, the dimensions of the preview windows and the scale factor. Scale factor permits you to calibrate the dimension of your entities on paper. If you want, for example, print the entities with the same dimension you have drawn them on viewport, you should set scale factor to 1.

Finally, if you prefer to print directly without displaying the preview window, you should use HiddenLinesViewOnPaper object instead of HiddenLinesViewOnPaperPreview.