Nobody else pointed out that you're code will leak resource and eventually crash Windows.
Those Font and Brush objects you're newing up need to have Dispose called on them to free up GDI resources. You cannot just new them up "fire and forget" style.
A much cleaner version of the code would look something like this:
Private Sub prnDocument_PrintPage(ByVal sender As Object, ByVal e As PrintPageEventArgs)
Dim g As Graphics = e.Graphics
g.PageUnit = GraphicsUnit.Point
Dim lalign As New StringFormat
lalign.Alignment = StringAlignment.Near
Using (Font font As New Font("Arial", 19))
Using (Brush brushBlack As New SolidBrush(Color.Black)
Dim lwi As Single = TextWidth("A", font)
g.DrawString("A", font, brushBlack, 10, 50, lalign)
g.DrawString("A", font, brushBlack, 10 + lwi, 50, lalign)
g.DrawString("A", font, brushBlack, 10 + lwi + lwi, 50, lalign)
End Using
End Using
End Sub