What a PDF watermark can and cannot protect

A watermark is a notice

Labels such as DRAFT, CONFIDENTIAL or SAMPLE can discourage casual misuse and communicate document status. They do not encrypt the PDF, stop screenshots or prevent an editor from removing page objects.

Balance visibility and readability

For a typical A4 draft, start near 22% opacity, 42 pt and −35°. Increase size before opacity when the label must span whitespace without hiding small text.

Apply the mark only to relevant pages when a title page or form must remain clean.

Worked example: external review

Add REVIEW COPY — 21 AUG 2026 to every page at medium opacity. The date distinguishes versions, but do not include a recipient’s personal information unless that disclosure is appropriate.

Use stronger controls when needed

For restricted material, use approved access controls, recipient agreements and secure sharing. A visual watermark can complement those controls but cannot replace them.