It's easy to convert images into PDF files -- whether on Windows, Mac, or directly on your mobile phone. We'll show you how it works.

Some might suggest you download an app to convert a picture to a PDF on the iPhone, but the truth is you can do it for free without any apps.

In the Preview app, for example, it's possible to create a single multi-page PDF document out of several separate image files.

How to Insert a Watermark in a PDF File. Watermarks are images or text displayed over the top of or underneath content in your PDF files to indicate information such as who owns the document, who ...