How to Watermark a PDF (and Get Arabic Text Right)
Add a text watermark to a PDF for free, including a real technical look at why Arabic watermark text is harder to get right than English.
Watermarking a PDF sounds simple — stamp some text across the page — until you try it with Arabic text and the watermark comes out as boxes, disconnected letters, or missing entirely. Here's how to watermark a PDF properly, and what's actually happening under the hood with Arabic text specifically.
Add a text watermark
Open Watermark PDF, type your text (a name, "CONFIDENTIAL", a company name), and choose its position, rotation, opacity and size. The watermark is drawn into every page of the document, not just displayed as an overlay — it's part of the saved file.
Why Arabic watermark text is a harder problem
Most PDF tools embed a small, fixed font — usually a Latin one — into the file. Arabic text needs a font that actually contains Arabic glyphs, and Arabic script also needs shaping (the same letter looks different at the start, middle or end of a word) and right-to-left layout, none of which a Latin-only font can do. That's why so many free watermark tools silently produce garbled Arabic or fall back to boxes.
How Convorae handles this
For Arabic watermark text, a proper Arabic font (Noto Sans Arabic) is fetched and embedded into the PDF along with your text — resolved so only the glyphs your specific text actually uses are included, keeping the file small. This is real, tested handling, not a guess: it was built and verified specifically because generic PDF libraries don't do this correctly out of the box.
Pick opacity and position deliberately
A watermark meant to deter copying (like "CONFIDENTIAL") usually works best diagonal, low-opacity, and centered so it can't be easily cropped out. A watermark meant to be read (like a company name in a footer) should be higher-opacity and positioned where it won't overlap body text.
Quick tips
- Test with your actual Arabic text before finalizing — mixed Arabic/English watermarks (a name plus a date) are supported.
- Lower opacity (10-20%) keeps a watermark visible without making the underlying text hard to read.
- The watermark is baked into the file itself — recipients can't toggle it off, but a determined person could still crop or edit it out; a watermark deters casual copying, it isn't DRM.