Full page border when printing

I’m trying to create a ForegroundTemplate that creates a Border around the full page when printed.

Like this:

This is where I’m stuck. I can see the border in the upper left but it doesn’t stretch to cover the entire page when printed:

<div style="text-align: left; : rgb248, 248, 252; ">      <DataTemplate x:Key="<span ="highlight">Print</span>BorderTemplate"><div style="text-align: left; : rgb248, 248, 252; ">            <go:SpotPanel><div style="text-align: left; : rgb248, 248, 252; ">                <!-- takes the size of each <span ="highlight">print</span>ed page --><div style="text-align: left; : rgb248, 248, 252; ">                <!-- header --><div style="text-align: left; : rgb248, 248, 252; ">                <TextBlock Text="{Binding Diagram.Model.Name}" FontSize="20"<div style="text-align: left; : rgb248, 248, 252; ">                            go:SpotPanel.Spot="MiddleTop" go:SpotPanel.Alignment="MiddleBottom" /><div style="text-align: left; : rgb248, 248, 252; ">
<span style="text-align: left; : rgb248, 248, 252; ">                <!-- Border that does not fill the entire page --></span><div style="text-align: left; : rgb248, 248, 252; ">                <Border go:SpotPanel.Spot="TopLeft" BorderBrush="Black" BorderThickness="2"></Border><div style="text-align: left; : rgb248, 248, 252; ">
<div style="text-align: left; : rgb248, 248, 252; ">            </go:SpotPanel><div style="text-align: left; : rgb248, 248, 252; ">        </DataTemplate>

How can I get this border to fill the whole page?

Forgot to mention.
I’m using GoXam 1.3.2.5 and Silverlight 5.

I would try putting the Border around the go:SpotPanel.