Protected Overrides ReadOnly Property CreateParams() As CreateParams
    Get
        ' Make background transparent
        Dim cp As CreateParams = MyBase.CreateParams
        cp.ExStyle = cp.ExStyle Or &H20
        Return cp
    End Get
End Property

Protected Overrides Sub OnPaintBackground(e As PaintEventArgs)
    '' call MyBase.OnPaintBackground(e) only if the backColor is not Color.Transparent
    If Me.BackColor <> Color.Transparent Then
        MyBase.OnPaintBackground(e)
    End If
End Sub