Tiling one Form with a part of another Form

[VisualBeginner.NET]

I want to tile one Form with a small portion of another Form. What am I doing wrong?

Public Class Form71

    Dim backImg As New Bitmap(Form70.Picture1.Image) ' 214 by 169
    Dim tBr As New TextureBrush(backImg, wrapMode:=Drawing2D.WrapMode.TileFlipXY)

'   Then we will replace the image with another one in Form_Load

    Private Sub Form71_Load(sender As Object, e As EventArgs) Handles MyBase.Load

        Dim NewImage As New Bitmap(80, 60)
        Using g As Graphics = Graphics.FromImage(NewImage)
            g.CopyFromScreen(Form70.Location.X, Form70.Location.Y, 400, 100, NewImage.Size)
'    One of these two things should work but neither is working
            g.DrawImage(Form70.frmImage, New Rectangle(400, 100, 80, 60))
        End Using
        tBr = New TextureBrush(NewImage, wrapMode:=Drawing2D.WrapMode.TileFlipXY)
        Me.Refresh()

    Private Sub Form71_Paint(sender As Object, e As PaintEventArgs) Handles Me.Paint
        e.Graphics.FillRectangle(tBr, ClientRectangle)
    End Sub