Watermark PDF

A watermark is a semi-transparent overlay applied to every page of a document. SwitchPDF supports two kinds: text watermarks (a string of letters drawn at a configurable rotation and opacity) and image watermarks (a PNG or JPG, typically a logo). Both are added as native PDF objects so they remain crisp at every zoom level and travel with the document everywhere it goes.

For text watermarks we embed the font into the PDF (Helvetica by default) and draw the text using a transparency operator that makes it semi-see-through. The classic "DRAFT" diagonal watermark is a 45° rotation at 30% opacity — but you can configure any angle and opacity from 10% to 100%. For image watermarks we embed the image as a Form XObject and place it at your chosen position on every page.

Common use cases: branding deliverables with a company logo before sending to a client; marking pre-publication documents as "CONFIDENTIAL" or "DRAFT"; stamping copyright notices on creative work; flagging internal-only versions of contracts. The watermark survives copy-paste and is part of the document's content stream — anyone who tries to remove it has to physically delete each watermark object, which is not trivial without specialized tools.

If you need the watermark to be a header or footer (different on different pages, with dynamic content like page numbers), use our Page Numbers tool or run Watermark PDF in batches with different page ranges.