How to use the Watermark PDF
- Add one or more PDFs; a whole batch can be stamped with the same text.
- Type the text, for example DRAFT or “Copy for Smith & Co”.
- Choose diagonal, centre, top or bottom placement, then opacity and colour (grey, red, black, green or orange).
- Press Watermark and download the stamped files.
Automatic sizing
You do not pick a font size. A diagonal stamp stretches across about 70% of the page’s diagonal and a horizontal one across about 80% of its width, so a short word is large and a long sentence smaller, on any paper size.
Around 20 to 30% opacity leaves the content easy to read. Raise it when the mark must be obvious on a photocopy or printout.
Wording that does its job
Single capitalised words such as DRAFT, SAMPLE or VOID read well at an angle. Adding a recipient name and a date makes it clear where a forwarded copy came from, which discourages passing it on.
Top or bottom placement suits a longer line, such as a firm name or “Not for distribution”, since horizontal text is easier to read across a page.
Limits worth knowing
The mark is written into each page as semi-transparent text, so it appears in every viewer, in print and in image exports. A person with a PDF editor can still remove it.
Only Western European characters can be drawn, which includes accented letters like é, ü and ñ. Other alphabets and logo images are not supported.
Questions
Can I watermark just some pages?
Yes. Under More settings type the pages, for example 1 or 2-end. Leave it empty to stamp every page.
Are the files uploaded?
No. The watermark is added with pdf-lib in your browser.
Can I make the stamp regular weight instead of bold?
Yes. Bold is on by default; untick it under More settings for a lighter look.