https://learn.microsoft.com/en-us/uwp/api/windows.ui.xaml.controls.inktoolbarstencilbutton?view=winrt-28000
InkToolbarStencilButton Class (Windows.UI.Xaml.Controls) - Windows apps | Microsoft Learn
Represents an InkToolbar button that sets the state of stencil tool to on or off.
classwindowsuixamlcontrols