The present invention relates to embedding a document with multiple watermark
components at different printing stages. A document is preprinted to include a
first digital watermark component. The document is then reprinted, perhaps with
a lower quality printer, to include a second digital watermark component. In some
cases the first component provides an orientation signal that is useful when trying
to detect the second component. In other cases the first and second components
are related or otherwise used to determine the authenticity of the document. In
still other cases, the first and second watermark components carry information
useful in determining the type of document, watermark-embedding hints and/or personal
or serialized data.