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.
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.
Fine-tuning
Other resources
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