With the Word document open go to Page Layout and in the Page Background section click on Watermark.
Now you can choose one of the included watermarks to fit the type of document or add a custom image.
To add a custom image click on Custom Watermark as the bottom of the menu. Notice this is where you can remove a watermark as well.
Now you can add your own custom text watermark or browse for an image such as a company logo. Here you can also select a custom font, color, layout, and size of the watermark.
That’s it! Now you will have the custom text or image watermark in your document.
This tutorial should definitely get you started on adding custom watermarks to your important documents.