A basic Style definition. The text in the TextBox is entered at runtime.
<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'> <Grid x:Name="LayoutRoot" Background="White"> <TextBox x:Name="myTextBox"> <TextBox.Style> <Style TargetType="TextBox"> <Setter Property="FontFamily" Value="Verdana"></Setter> <Setter Property="FontSize" Value="12"></Setter> <Setter Property="FontWeight" Value="Bold"></Setter> <Setter Property="Height" Value="24"></Setter> <Setter Property="Width" Value="180"></Setter> </Style> </TextBox.Style> </TextBox> </Grid> </UserControl>