Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As _
  System.EventArgs) Handles MyBase.Load
        Me.RichTextBox1.Text = "Das ist meine Richtextbox"
    End Sub
 
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles Button1.Click
        Dim pd As New System.Drawing.Printing.PrintDocument
        AddHandler pd.PrintPage, AddressOf PrintPage
        PrintPreviewDialog1.Document = pd
        PrintPreviewDialog1.ShowDialog()
    End Sub
 
    Public Sub PrintPage(ByVal sender As Object, ByVal e As _
      System.Drawing.Printing.PrintPageEventArgs)
        Dim TextFont As New Font("Courier New", 16, FontStyle.Regular)          _
               'TextFont
        e.Graphics.DrawString(Me.RichTextBox1.Text, TextFont, Brushes.Black, 0, _
        0)
    End Sub