Gets or sets the layers a page render draws: the content, the annotations and the form fields, in that order; All by default.
public DisplayLayers Layers { get; set; }
ISO 32000-2 §12.5 and §12.7, through CreateDisplayList(DisplayLayers, DisplayIntent, ContentOptions). A viewer that redraws overlays without re-rasterizing the page builds each layer's list itself and replays them with Render(DisplayList, Bitmap, in Matrix).