## Supported files

You can watermark PDF and EPUB files. Other file types are refused with **Only PDF and EPUB files are supported.**

## PDF copies

The stamp text is written once on every page. It runs diagonally across the middle of the page in bold, using the colour and opacity you choose. The text size scales with the page size.

## EPUB copies

The stamp text is added as a small, centred line at the top and at the bottom of every chapter, using your colour and opacity. Reading apps show it as part of the text, so it reflows with the book.

## Hidden marks

Every copy also carries hidden marks that point back to the reader, on top of the visible stamp. They stay in the file even if someone removes the visible stamp. If you find a leaked copy, upload it to **Leak Detector** to find out whose copy it was.

## What the text says

In single-file mode, the stamp is exactly what's in **Reviewer Text**.

In batch mode, each copy uses the selected **Watermark Template** with the reader's details filled in. Templates can use two placeholders:

- {{name}} for the reader's name
- {{email}} for the reader's email

For example, the built-in Review Copy template is REVIEW COPY - {{name}} - {{email}}.

## File names

Each copy is named after your file plus the reader's name, so you can tell them apart. For example, my-book-Jane_Smith.pdf.