Where's DrawingBrush on Windows Metro for XAML

I am writing a Windows Metro XAML application in C # and I want to draw grid lines with a brush on my custom grid control.

In WPF, I would create a DrawingBrush to do this work, but there seems to be no equivalent in Metro.

Does anyone know if this function exists under a different name or that you will achieve the same result differently?

As an additional note, I do not want to draw lines, etc. directly on my grid (adding lines to my collection of baby panels). This really needs to be done through the background property - for example, a brush.

thank