Watermarks: Thin, translucent paper embed with a pattern or picture which can be viewed when held as much as gentle. Exhibit A: for my part, a genuine 1876-cc DDR. Obtained (cherrypicked!) from the well known eBay vendor who's got loads of trade dollars, usually "blast white." I've examined it minutely; https://juliant826bku2.blogdomago.com/34059121/the-copyright-to-print-diaries