The Complete Guide to PDF Watermarking
Text and image marks, placement, rotation, opacity, and tiling — all in your browser.
1. Text vs Image Watermarks
Text watermarks win for copyright notices, draft status ("DRAFT","CONFIDENTIAL"), and any mark where the wording matters more than the brand. They scale infinitely, are readable in any PDF viewer, and never pixelate. Image watermarks (logos, signatures, brand graphics) win for visual identity — use a PNG with transparency so the watermark blends instead of stamping an opaque rectangle. This tool handles both with the same position, opacity, rotation, and page-range controls.
2. Position: corners, center, and tiled
Corners keep the mark out of the reading flow — bottom-right is the conventional copyright spot, mirroring footer credit lines. Center is the strongest visual treatment and the right choice for"DRAFT" or"CONFIDENTIAL" status. Tiled repeats the mark across the entire page in a grid pattern, giving you the strongest deterrent against screenshot theft. Tiled on a -45° rotation creates the classic repeating diagonal grid you see on architectural plans and stock previews.
3. Opacity, rotation, and color
Aim for 30–45% opacity on copyright marks — visible enough to deter screenshots, faint enough to live inside printed material. Push to 60–80% for draft and confidential marks where the status must be unmistakable. Rotation of -45° produces the conventional diagonal; 0° yields a flat horizontal stamp. Color should contrast subtly with the page — a violet or dark gray reads as elegant on white text PDFs; pure black can feel heavy.
4. Page ranges and selective watermarking
Type a page range (e.g. 1-3, 5, 9-) to watermark only those pages, or click page thumbnails to toggle individual selection. Leave both blank to stamp every page. Combining a range list with the thumbnail selection gives you precise control — watermark only the cover page, only the first page of each chapter, or every page except the index.
5. Privacy
Every step runs in your browser via pdf-lib (stamping) and pdfjs-dist (live preview rasterization). Your PDF and your watermark image never leave the device. Closing the tab clears the working set immediately. For NDAs, board memos, medical records, or unreleased reports, browser-side watermarking is the only structurally private approach.
Conclusion
Watermarking is one of the fastest ways to add ownership or status markings to a document — and one of the easiest to do entirely in the browser. Pick text for copyright notices and draft labels, image for logos and signatures; choose corners for restraint, center for emphasis, tiled for deterrence; and dial opacity, rotation, and color to taste. With page-range and thumbnail selection for precise targeting, a live preview so you see exactly what you ship, and a privacy model that keeps every byte on your device, this is the safe, fast way to stamp any PDF.