Refers to watermarks that are darker than the surrounding area on the sheet. A shaded watermark is produced by a depression in the sheet mold wire; when wet pulp flows into the recesses, the design is formed as different gradations of tone. The intaglio design, as opposed to a relief design, results in a thickening of the sheet at the point of contact, creating an opaque, or "shaded," design. It is a rather rare type of watermark; it has been produced since the early 19th century.
