This article is for developers seeking help on how to add a watermark programmatically within a PDF. A watermark is a recognizable image or pattern, a common way to identify work and discourage its unauthorized use. A visible watermark can’t prevent unauthorized use. But it makes it more difficult for people who want to claim someone else’s photo or artwork as their own.
In PDF, a watermark is text or an image that appears either in front of or behind existing document content, like a stamp. For example, you could apply a “Confidential” watermark to pages with sensitive information. You can add multiple watermarks to one or more PDFs, but it's necessary to add each watermark separately. You can specify the page or range of pages on which each watermark appears.