Why add a watermark to a PDF?
Watermarks serve several important purposes. They mark a document as confidential, preventing unauthorised sharing. They indicate a document is a draft, not the final version. They identify the source or owner. They brand documents for professional presentation. They mark invoices and receipts as VOID or SAMPLE to prevent fraudulent use.
Common watermark text
CONFIDENTIAL for sensitive business documents and legal contracts. DRAFT for documents under review. SAMPLE for example documents and proposals sent before payment. COPY for duplicates of originals. VOID for cancelled invoices. Your company name for branded document distribution.
Watermark opacity and visibility
A diagonal watermark is harder to remove than a horizontal one because it overlaps text and whitespace across every page. Lower opacity (20 to 30 percent) makes the watermark visible without obscuring content. Higher opacity (50 to 70 percent) creates a more prominent security marking visible even in poor quality scans or photocopies.
Frequently Asked Questions
Can a watermark be removed? A text watermark embedded using pdf-lib can be removed by someone with advanced PDF editing tools. For maximum security, use a high-opacity watermark that covers significant portions of the document content.
Is my PDF uploaded to a server? No. Everything runs in your browser. Your file never leaves your device.
Will the watermark appear on printed copies? Yes. The watermark is embedded in the PDF and will appear on all printed copies and scanned versions.
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