http://blogs.msdn.com/jnak/archive/2006/11/08/help-us-name-the-adorner-placement-apis.aspxLooking back to my most recent article on adorners you'll recall that we had this API on AdornerPanel that allowed the Control Developer to specify where and with what size their design time adorners were positioned on the design surface: AdornerPanel.SetHorizontalStretch(_slider,en-USCommunityServer 2.1 SP1 (Build: 61025.2)