How can I apply a watermark on every page of a PDF file?

Question

I have a PDF file and want to apply a watermark like the following on all pages and at 45 degrees:

watermark watermark watermark watermark watermark watermark watermark
watermark watermark watermark watermark watermark watermark watermark
watermark watermark watermark watermark watermark watermark watermark
watermark watermark watermark watermark watermark watermark watermark
watermark watermark watermark watermark watermark watermark watermark
watermark watermark watermark watermark watermark watermark watermark
........................

How can I do this?

Answer 1

Many ways:

• Use a commercial program (random example)
• Use whatever tool was used to create the PDF (e.g. Acrobat)
• Convert the PDF to a more tractable form.
  • e.g. pdftops or pdf2ps - then edit the PostScript to add the watermark and convert back to PDF

Answer 2

Create a PDF with your watermarks and stamp the original PDF with such a tool: http://pdftools.softonic.de/