When a watermark helps
A watermark tells every reader how a document should be treated before they read a word. CONFIDENTIAL on a salary list or a contract reminds people not to forward it. DRAFT on a proposal stops an unfinished version being signed or quoted. COPY or SAMPLE on a certificate or an invoice shows that the page is not the original. Many people also stamp their company name across a quotation or a design before sending it, so the file is less likely to be reused as someone else's work.
Centre or repeated, and which angle
"Once, in the centre" puts one large mark in the middle of each page, which is the usual style for DRAFT and CONFIDENTIAL. "Repeated across the page" tiles the text in staggered rows, which is harder to crop out of a screenshot or a scan and suits ID copies and photos of documents. The diagonal angle crosses the most text and is the classic look; straight text is easier to read and suits a company name. Opacity between 15% and 30% keeps the page readable when printed.
Watermarking ID and passport copies
When a landlord, an agent or a bank asks for a copy of your passport, Emirates ID or residence permit, a tiled watermark such as "Copy for tenancy, Oct 2026" limits what that copy can be reused for. Type the purpose and the date as the text, choose the repeated layout and a low opacity so the details stay readable, and send the watermarked PDF instead of the plain scan. Because the file is processed in your browser, the ID copy is not uploaded to us.
Arabic and other scripts
English text is added as real text in Helvetica Bold, a standard PDF font, so it stays sharp at any zoom and prints cleanly. The standard fonts cannot write Arabic, Urdu or other non-Latin scripts, so that text is drawn on your device and added as a high-resolution picture of the text, joined and right-to-left as it should be. It looks the same on screen and on paper, but it cannot be selected or searched.
Limits, honestly
A watermark is a visible label, not protection. Anyone with a PDF editor can cover or remove it, and it does not lock, encrypt or sign the file. The original text under the watermark is not changed, so it can still be selected and copied. Pages that were rotated or have mixed sizes each get the mark placed the right way up. Files up to 200 MB work on most computers; very large scans may be slow on older phones.