What I have at the moment is only defined width:
<Grid>
<Rectangle Fill="#FFF5F7F9" HorizontalAlignment="Left" Height="80" Stroke="#FF565656" VerticalAlignment="Top" Width="128" RadiusY="15" StrokeThickness="3" RadiusX="15"/>
<TextBlock HorizontalAlignment="Left" Height="47" TextWrapping="Wrap" Text="Draft" VerticalAlignment="Top" Width="106" FontSize="32" FontStyle="Italic" FontFamily="Verdana" Margin="20,21,0,0"/>
</Grid>
Something equivalent to html like (just for example):
<div style="display:inline;border:solid 3px #000;padding:3px">
Some text here
</div>