A watermark is text or a picture that sits behind your text and pictures, usually faint or washed-out so that it doesn't interfere with what's on the page. Like headers and footers, a watermark usually appears on all the pages of your document, except a cover page.
To add a watermark to your Word document, go to the Design tab and select Watermark. Select from the links below for additional information about how to work with watermarks.
Note
The best way to work with watermarks is in Word on a laptop or desktop computer, rather than in a web browser or mobile app.