Using MS-Word, always been able to add a watermark. It shows in the main doc but is not printed.?

I used to be able to add a watermark to a document but now that has changed doing exactly as I had before. It does show up in the main document I am working on but does not print and is not displayed when I go to 'print preview'. In most cases these documents are greeting cards that the recipient would like to print but now cannot print the watermark (background)