GCHR/Themes/Generic.xaml

<ResourceDictionary
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="clr-namespace:GCHR"
    xmlns:printing="clr-namespace:GCHR.Control.Printing">


    <Style TargetType="{x:Type printing:PageElement}">
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="{x:Type printing:PageElement}">
                    <Border Background="{TemplateBinding Background}"
                            BorderBrush="{TemplateBinding BorderBrush}"
                            BorderThickness="{TemplateBinding BorderThickness}">
                    </Border>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>
</ResourceDictionary>