xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" x:Class="Microsoft.Samples.Graphics.RectangleExample" WindowTitle="Example"> Name="MyFadingText" Margin="20" Width="640" Height="100" FontSize="48" FontWeight="Bold" Foreground="Maroon"> This is fading text Storyboard.TargetName="MyFadingText" Storyboard.TargetProperty="(TextBlock.Opacity)" From="1.0" To="0.0" Duration="0:0:5" AutoReverse="True" RepeatBehavior="Forever" />