How to Add a Watermark to a PDF
Watermarks deter unauthorized reproduction, signal document status (Draft, Approved, Confidential), and identify intended recipients. PDFPuddle adds watermarks directly to the page content stream — making them part of the PDF, not a removable layer.
Why watermarks matter
Marking a draft as DRAFT prevents someone forwarding it as final. Stamping CONFIDENTIAL across a contract reminds recipients of their obligations. Adding a recipient's name to a distributed copy creates accountability if the document leaks. All of these add friction without preventing legitimate use.
Configuring the watermark
Set the text (default CONFIDENTIAL), font size, opacity (0 = invisible, 1 = solid), and rotation angle. For background watermarks, opacity 0.10–0.20 and rotation -45° gives the classic diagonal grey stamp. For prominent stamps, increase opacity to 0.40–0.60.
Layered vs embedded watermarks
Some PDF tools add watermarks as a separate layer that recipients can disable in Acrobat. PDFPuddle draws the watermark directly into each page's content stream — it's part of the page itself, much harder to remove.
When NOT to watermark
Documents that need to be OCR'd later — heavy watermarks confuse OCR engines. Documents going through automated processing — the watermark text may be picked up as content. For those cases, watermark a separate distribution copy and keep the clean original.