Begin by Command-clicking in the margin. That takes the focus off the Text Layer and assures that the text box you are about to add will be a Floating objecct.
Then, Insert > Text Box.
Go to the Wrap Inspector and deselect the Object Causes Wrap feature.
Type the word Draft into the Text Box.
Select the word Draft and set the Font Size to something on the order of 200 points. Resize the text box to reveal the entire word, if necessary
In the Format Bar, click the black color block to the right of the font size selection box and select a gray color of your choice.
Select the text box and place the pointer over one of the corners. Hold down the Command key and the double-arrow cursor will change from straight to curved. Drag the corner to change the angle of the box. Reposition the box if necessary.
With the Text Box still Selected, choose: Arrange > Send Objects to Background.
If you only want the word Draft to appear on that one page, you're done. If you want it to appear on every page, continue...
Move your pointer to the margin. Hold down the Command key and Drag diagonally across the page to select the background text box.
Choose: Format > Advanced > Move Object to Section Master.
You'll get something like this:
Thanks for the post but I am having difficulty getting the watermark to repeat throughout the document. I completed the final step in the instructions but the watermark still only appears on the first page. I was wondering if there might be a difficulty that I have already have a lot of formatting in the document. I know I could have the printer insert the watermark but I was wanting to create a pdf.
The last step in Jerry's instructions is to "move the object to the section master."
Doing so makes the object—in this case, the text box containing the word "DRAFT"—appear on each page in the section. If your watermark is appearing on only one page, I suspect you have placed a section break at the end of the first page. Try copying the text box, pasting it to the second page, positioning as desired, and moving it to the section master on that page.
Your diagnosis was correct. I noticed in the section layout that the first page configuration was different but so too were the left and right pages because it has been formatted to be bound and printed on both sides. I suspect it might be easier putting a comment across the header.
Thanks for your assistance.