A watermark is a semi-transparent image that usually contains a logo or seal to identify who created a document or image. If you want to watermark a PDF file, you can either insert the watermark ...

Outlook 2013 supports the inclusion of JPG, GIF, PNG and BMP image files directly in a signature. To add a PDF image, you must include it as a Web link.

To convert a JPG file to a PDF file, simply change the file format on your computer's default photo-viewing app.