No.
QlikView uses a watermark to indicate that a document has been parked on a test server, and only as background of graphical charts. But unfortunately you cannot use this feature for your own purposes.
The alternative is the following: in a bitmap editor, create a picture with a transparent background and a large "Test" in the foreground. Save it as a JPG or PNG file. Then in QV Desktop, open Settings->Properties->General and change the Default Sheet Background to include your picture. Position it according to your needs and document layout.
All sheets that don't have a customized background will now include this "Test" picture. The technique makes it easy to remove the "Test" text whenever a document is moving to Production.
