Add watermark to PDF

Type the words, pick a font (sans, serif or mono, regular or bold), a size in points and a colour. Latin, Greek and Cyrillic letters work, so ЧЕРНОВИК and ΠΡΟΧΕΙΡΟ are fine; a character the fonts don’t have is named so you can change it.

For a logo, choose a PNG, JPG or WebP picture and set how wide it is as a share of the page. A PNG keeps its own transparency. The picture is written into the PDF once and shown on each page, so a logo on a long document adds its size only once.

Opacity runs from nearly invisible to solid, and 30% is a good start for text across a page. Turn the watermark with the slider: 45° is the usual diagonal, 0° keeps it straight.

Put it in the middle, in a corner or along an edge, or tile it so it repeats across the whole page in staggered rows, the way a “CONFIDENTIAL” stamp covers a contract. Pages are drawn as you see them, so rotated and cropped pages get the watermark in the right place.

Choose whether it goes over the page’s own content or under it. Under keeps text and pictures in front, but a white box or a picture that covers the page hides the watermark where it lies.

Leave Pages empty to watermark every page, or type the ones you want, such as 1-3, 5. Pages a PDF doesn’t have are left out, so one setting serves several PDFs.

Each PDF saves as a copy named after it, like report-watermarked.pdf, and your original is untouched. Everything already in the PDF stays: text you can select, photos, links, form fields and bookmarks. A digital signature no longer checks out afterwards, as after any change to a signed file.

A PDF protected with a password asks for it on the file before it opens, and the watermarked copy has no password. One whose owner doesn’t allow changes says so: Unlock PDF takes that off first, and the others are watermarked as usual.