A watermark annotation: graphics printed at a fixed size and position relative to the media.
public sealed class PdfWatermarkAnnotation : PdfAnnotation
ISO 32000-2 §12.5.6.22, Table 193 (PDF 1.6). It has no pop-up window or other interactive elements.
kind:method, kind:property, kind:ctor. Press Esc to clear.FixedPrintGets the fixed print dictionary (FixedPrint), or null when the annotation is drawn without regard to the media.