Before you start
PDF watermarking is a paid-plan feature — Basic, Pro and Enterprise stores only. Free-plan stores see an "Upgrade to enable PDF watermarking" prompt in place of the settings page. You also need at least one PDF product mapping in the store, otherwise there's nothing to watermark.
How watermarking works
Alva Digital Downloads holds every paid order containing a watermark-enabled PDF product briefly while the file is stamped with the buyer's details, then releases the download email. The original file in your library is never modified — each customer gets their own stamped copy. Each stamped PDF also carries an invisible forensic marker that ties the file back to the order, so leaked copies can be traced to a specific buyer.
Set up your watermark defaults
1. Open Settings
Open Alva Digital Downloads in your Shopify admin and click Settings in the side navigation. The Settings hub lists every configuration card available on your current plan.
2. Open the PDF Watermarking card
Find the PDF Watermarking card on the Settings hub and click Configure. The watermarking settings page opens with the defaults panel where you set how the watermark looks.
3. Configure your watermark defaults
Set the watermark template text, position, opacity and colour in the defaults panel. These defaults apply to every product you watermark, and you can fine-tune them at any time.
4. Save your defaults
Click Save in the SaveBar that appears at the bottom of the screen. Saving stores your watermark configuration — it does not stamp anything on its own. Stamping is switched on per product, which is the next step.
Pick your defaults
On the same PDF Watermarking page, you also choose the default template, position, opacity, color, font size, and which layers run — text overlay, footer text, and invisible forensic markers. These defaults apply to every watermark-enabled product unless you customise the values on the individual product later. See the follow-up articles on writing the template, choosing position and opacity, and the variables you can interpolate for details.
Opt products in
Saving your watermark defaults does not stamp anything on its own — watermarking is opt-in per product. Each product mapping has its own Enable PDF watermarking toggle, and Alva Digital Downloads only stamps files for mappings where that toggle is on. Open each PDF product mapping individually and switch it on — see Enable PDF watermarking on a specific product for the step-by-step.
What customers see
Customers receive the same delivery email and download page as before, except the PDFs are now personalised with their order details. For online orders, Alva Digital Downloads holds the email back until all stamps complete — typically 1–3 seconds, longer for large files. For Shopify POS orders, the email goes out immediately and the first re-download serves the stamped version once stamping finishes in the background.
Limitations
- PDFs only — non-PDF files (videos, audio, ZIPs, images) pass through unchanged.
- Encrypted or password-protected PDFs are rejected by the safety checks and pass through unchanged.
- PDFs over 100 MB are not stamped — they pass through unchanged.
- Personalised products are never stamped — the personalisation itself acts as the watermark.
- User-uploaded ZIP archives are not unpacked, so PDFs inside a customer-supplied ZIP are not stamped.
Frequently asked questions
No. PDF watermarking is available on the Basic, Pro and Enterprise plans. On Free plan, the PDF Watermarking settings page is locked and the per-product toggle is hidden. Upgrade your plan to enable it.
No, existing files in your library stay unchanged. Stamping happens at order time, once per customer. The first time a previous customer re-downloads a PDF for an order placed after you opted that product in, Alva Digital Downloads stamps the file lazily and serves the stamped copy.
Yes for the visible overlay (you control its opacity and position) and no for the forensic marker, which is embedded invisibly in the PDF structure. If you only need the forensic trace and don't want a visible mark, turn the visible-overlay layer off and keep the forensic layer on.
See also
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Last updated 2026-05-28