Every page gets the same treatment: your text in bold gray Helvetica, tilted −35° and centred, so it reads across the middle of the content without hiding it. Opacity is the one style control — there is a single watermark look per run, chosen to stay readable yet unobtrusive. The text is drawn with the PDF’s built-in font, which covers Latin letters, digits and common punctuation; emoji and non-Latin scripts fall back to a “?” placeholder rather than crashing the download. Everything runs locally in your browser — your document is never uploaded.
Be clear about what a watermark is: a visual label that travels with printed and digital copies, telling readers a contract is a draft, a document is confidential, or a form is a specimen copy. It does not encrypt the file or stop anyone from copying or extracting the text underneath, so treat it as communication rather than protection. For drafts that circulate internally before signing, combine it with page numbers so reviewers can quote exact pages, then merge the approved pages into the final document.
Also useful: PDF Page Numbers, Compress PDF, and Merge PDF.