Create a Watermark
The Problem:
I need to stamp "DRAFT" in red across each page of my report. I can put a floating graphic on each page, but they tend to move even if I try to anchor them.
The Solution:
Word considers this to be a watermark. Choose Format 
Background Printed Watermark and use the options in the Printed Watermark dialog box.
To create a watermark, Word uses the header-and-footer layer. If the canned options in the Printed Watermark dialog box don't give you enough flexibility, you can tweak the watermark by choosing View Header and Footer and working with the watermark directly. The header-and-footer layer is a special layer that enables you to position text or graphics anywhere on the page, not just in the areas conventionally reserved for headers and footers.