Repeat a background brush in WPF

Question

and thank you.

This question is very similar to this old, unanswered question here: How to paint notebook-like lines as TextBox background? However, it is not the same - not exactly.

I would like to create a notepad, lined paper-like background but I am not not familiar with how to repeat a brush in XAML. How do you?

EDIT

Here's the solution as part of a TextBox:

<TextBox TextBlock.LineHeight="20" 
         TextBlock.LineStackingStrategy="BlockLineHeight" 
         Padding="20,10,20,20" TextWrapping="Wrap">
  <TextBox.Background>
    <DrawingBrush TileMode="Tile" Stretch="None" Viewport="0,0,20,20" 
                  ViewportUnits="Absolute" Opacity=".07">
      <DrawingBrush.Drawing>
          <GeometryDrawing>
              <GeometryDrawing.Pen>
                  <Pen Brush="RoyalBlue" />
              </GeometryDrawing.Pen>
              <GeometryDrawing.Geometry>
                  <LineGeometry StartPoint="0,0" EndPoint="20,0"/>
              </GeometryDrawing.Geometry>
          </GeometryDrawing>
      </DrawingBrush.Drawing>
    </DrawingBrush>
  </TextBox.Background>
  Now is the time for all good men to come to the aid of their country.
  Now is the time for all good men to come to the aid of their country.
  Now is the time for all good men to come to the aid of their country.
  Now is the time for all good men to come to the aid of their country.
  Now is the time for all good men to come to the aid of their country.
</TextBox>

Answer 1

<DrawingBrush TileMode="Tile" Stretch="None"
              Viewport="0,0,20,20" ViewportUnits="Absolute">
    <DrawingBrush.Drawing>
        <GeometryDrawing>
            <GeometryDrawing.Pen>
                <Pen Brush="Gray"/>
            </GeometryDrawing.Pen>
            <GeometryDrawing.Geometry>
                <LineGeometry StartPoint="0,0"
                              EndPoint="20,0"/>
            </GeometryDrawing.Geometry>
        </GeometryDrawing>
    </DrawingBrush.Drawing>
</DrawingBrush>