Define a border around a single Button control setting the BorderThickness and BorderBrush properties
<UserControl x:Class='SilverlightApplication3.MainPage' xmlns='http://schemas.microsoft.com/winfx/2006/xaml/presentation' xmlns:x='http://schemas.microsoft.com/winfx/2006/xaml' xmlns:d='http://schemas.microsoft.com/expression/blend/2008' xmlns:mc='http://schemas.openxmlformats.org/markup-compatibility/2006' mc:Ignorable='d' d:DesignWidth='640' d:DesignHeight='480'> <Border BorderThickness="5" BorderBrush="Blue" Background="LightGray" Height="100" Width="250"> <Button Content="Bordered Button" Height="50" Width="200" /> </Border> </UserControl>