You've created a PDF document and need to mark it as confidential, protect your copyright, add company branding, or track who receives copies. Watermarks solve this problem by adding visible text or images to your PDF pages—"CONFIDENTIAL" across sensitive reports, company logos on proposals, or "DRAFT" on unfinished documents. Watermarking makes ownership clear, discourages unauthorized sharing, and helps identify the source of leaked documents. This guide explains everything you need to know about adding watermarks to PDF documents in clear, practical terms. You'll learn what watermarks are, the difference between text and image watermarks, how watermarks actually protect documents (and their significant limitations), security considerations when using online tools, and when watermarking makes sense versus other protection methods. What is a PDF Watermark? A PDF watermark is fixed text or an image added to document pages to indicate ownership, display brand...