DrawingBrush Opacity from 1 to 0
<Window x:Class="Workspace.DockExample" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" Title="Workspace" Width="640" Height="480"> <Window.Resources> <DrawingGroup x:Key="myDrawing"> <DrawingGroup.Children> <GeometryDrawing> <GeometryDrawing.Geometry> <GeometryGroup> <LineGeometry StartPoint="0,0" EndPoint="1,1" /> <LineGeometry StartPoint="0,1" EndPoint="1,0" /> </GeometryGroup> </GeometryDrawing.Geometry> <GeometryDrawing.Pen> <Pen Thickness="0.2" Brush="#3366FF" /> </GeometryDrawing.Pen> </GeometryDrawing> <GeometryDrawing Brush="Red" Geometry="M 0.4,0.4 L 0.5,0.2 0.6,0.4 0.5,0.5" /> <GeometryDrawing Brush="Black" Geometry="M 0.4,0.4 L 0.2,0.5 0.4,0.6 0.5,0.5" /> </DrawingGroup.Children> </DrawingGroup> </Window.Resources> <StackPanel> <Rectangle Width="100" Height="50" Stroke="Black" StrokeThickness="1"> <Rectangle.Fill> <DrawingBrush Drawing="{StaticResource myDrawing}" Opacity="1.0" /> </Rectangle.Fill> </Rectangle> <Rectangle Width="100" Height="50" Stroke="Black" StrokeThickness="1"> <Rectangle.Fill> <DrawingBrush Drawing="{StaticResource myDrawing}" Opacity="0.75" /> </Rectangle.Fill> </Rectangle> <Rectangle Width="100" Height="50" Stroke="Black" StrokeThickness="1"> <Rectangle.Fill> <DrawingBrush Drawing="{StaticResource myDrawing}" Opacity="0.5" /> </Rectangle.Fill> </Rectangle> <Rectangle Width="100" Height="50" Stroke="Black" StrokeThickness="1"> <Rectangle.Fill> <DrawingBrush Drawing="{StaticResource myDrawing}" Opacity="0.25" /> </Rectangle.Fill> </Rectangle> <Rectangle Width="100" Height="50" Stroke="Black" StrokeThickness="1"> <Rectangle.Fill> <DrawingBrush Drawing="{StaticResource myDrawing}" Opacity="0" /> </Rectangle.Fill> </Rectangle> </StackPanel> </Window>