First ...
... let's use the jungle border for this tutorial.
You should use the .WMF, .EPS, or .PDF format for this process (.GIF and .JPG will work if nothing else is available). View the downloading clip art tutorial if you need help downloading your image.
Second ...
... Open your Word document. On the Format menu, point to Background and then click Printed Watermark.
Third ...
... click Picture Watermark, and uncheck the Washout button. If you use the Washout button it will make the image faded so you can read the text better.
Fourth ...
... Click Select Picture and browse to the folder you saved your image to in step 1. Click Insert and then OK. Your image will appear in your Word document.
Fifth ...
... That's it! You may need to adjust your margins before you begin typing to make sure your text is visible and easy to read on the image.
