How to Add a Watermark to a PDF
Watermarking a PDF is common for marking drafts, protecting confidential documents, or adding a company logo across every page, but a poorly configured watermark can end up making the document harder to read than it protects.
Text watermarks vs. image watermarks
A text watermark, like 'DRAFT' or 'CONFIDENTIAL', is quick to set up and works well for internal documents. An image watermark, like a company logo, takes a bit more setup but looks more polished for anything client-facing or public.
Getting opacity right
The most common watermarking mistake is leaving the opacity too high, which makes the underlying text hard to read. A lower opacity setting, generally in the 10-20% range, is usually enough to be visible without interfering with readability, especially for text-heavy documents.
Placement and rotation
A diagonal watermark placed across the center of the page is the standard choice because it's hard to crop out and doesn't sit directly on top of any single line of text. A watermark placed in a corner is easier to read past, but is also easier for someone to simply crop off if the point is to discourage misuse.
Applying to specific pages only
You don't always need a watermark on every page. Some tools let you apply it only to specific pages, like just the cover page for a draft stamp, or skip watermarking on pages that are purely blank or purely images, which can matter for documents you want to look professional in some sections and clearly marked as a draft in others.
