Aug 02, 2026 · 4 min read · Edit

Stamping Letterhead, Watermarks or Forms Over a PDF

Letterhead behind a letter, a DRAFT stamp across every page, typed answers laid over a scanned form - all the same operation: drawing one PDF on top (or underneath) another.

How to use it

1. Open Overlay PDF and choose two files: the base document, then the stamp.
2. Choose whether the stamp goes on top or behind the content, and whether one stamp page repeats across every base page.
3. Process and download the combined document.

Try it now: open the Overlay PDF tool - no account, no upload, free.

What happens under the hood

The stamp’s pages are embedded as vector form objects and drawn into each base page’s content stream - before existing content for “behind”, after it for “on top”, with adjustable opacity. Vector-in, vector-out: nothing is rasterized.

Tips for better results

• For letterhead, put the stamp behind - body text prints over the letterhead graphics exactly like a preprinted sheet.
• A one-page stamp with “repeat” on is the classic every-page watermark template.

Privacy, in one sentence

Your file is read into your browser's memory, processed there by JavaScript and WebAssembly, and handed back to you as a download - no server ever sees a byte of it. Close the tab and nothing remains.