# Tracing Marks (/docs/tracing-marks) A visible watermark can be cropped, covered or edited out. **Tracing marks** hide each download's [copy code](/docs/copy-tracking) inside the PDF, in places a leaker is unlikely to notice. If the file turns up online, [Leak tracing](/docs/leak-tracing) can read the marks and tell you whose download it was. You'll find them under **Settings → Tracing Marks**. ![Tracing Marks settings](/images/tracing-marks.webp) --- ## 🕵️ What the Marks Are [#️-what-the-marks-are] Every download gets its own copy code. With tracing marks on, each copy carries that code in up to three places: - **Micro-text:** the code in tiny text in the bottom-left margin of every page, too faint to see when reading or printing. - **Document properties:** the copy code and the order's licence code are saved in the file's properties, the hidden details where PDF readers keep things like the title and author. - **QR code (optional):** a small QR code of about 1 cm holding the copy code, in a corner of every page. Unlike the other marks, it's visible. --- ## 🟢 Invisible Marks [#-invisible-marks] Switch on **Add invisible tracing marks** in the **Invisible marks** section, then save. - **They work without the watermark.** Marks are added with the watermark off, with **Apply to all PDFs** off, and on products whose watermark is disabled. - **They go on every page**, even when **First page only** is on for your watermark. - **Every PDF download is processed while this is on.** If you switched off the watermark on a very large PDF so it downloads faster, keep in mind that tracing marks still process it. - **A download is never blocked.** If the marks can't be added to a file, your customer still gets the original PDF, just without marks. - **PDFs with a permissions password** (one that restricts printing, copying or editing) are sent unchanged, without marks, when no watermark applies to them. That way their restrictions stay in place. **Default:** new stores start with the invisible marks on. Stores that were already using Imprint before tracing marks arrived start with them off, so switch them on yourself. The QR code starts off for everyone. --- ## 🔳 QR Code [#-qr-code] The QR code is the one mark that survives printing, scanning and screenshots, as long as it stays visible on the page. That's why we recommend turning it on. - **Add a QR code:** can only be switched on while the invisible marks are on. - **QR code corner:** **Top Left**, **Top Right**, **Bottom Left** or **Bottom Right** (the default). - **QR code opacity:** **50%**, **65%**, **80%** (the default) or **100%**. 50% is the lightest setting that still scans reliably. A few placement tips: - The code sits on a small white square (about 1.5 cm) that hides whatever is underneath it. Pick a corner that is usually empty in your PDFs, away from page numbers or footers. - It doesn't move out of the way of your watermark. If your stamp is in the same corner, they overlap. The [Watermark Settings](/docs/watermark-settings) preview shows the QR code, so you can place the stamp somewhere else. - You can scan the code with your phone's camera. It shows the copy code, which you can paste into **Find Order by Code** on the [Orders](/docs/orders) page. --- ## 👀 Preview [#-preview] The **Preview** at the bottom of the page shows a sample page with the QR code in the corner you picked. When the marks are off, it says **"Tracing marks are off, so downloads carry no hidden copy code."** To check a real file, open a product and click **Preview PDF Stamp**. It shows your own PDF with the tracing marks and a sample copy code, even when the watermark is off for that product. --- ## 🧽 What Can Remove the Marks [#-what-can-remove-the-marks] No mark is impossible to remove, so it helps to know the limits: - **Printing to images, scanning, photos and screenshots** remove the hidden micro-text and the document properties. The QR code survives if it's still visible on the page and readable. - **Cropping the margins or a corner**, or covering the QR code, can remove the micro-text or the QR code. - **Some PDF tools** clear the document properties when they save a file. - **Downloads made before the marks were on** don't carry them. Each mark can be lost in a different way, so a copy rarely loses all of them. Together with the visible watermark, they give you the best chance of tracing a leak. Copies downloaded with tracing marks on can usually be traced, but not always. --- ## 🔗 Related Pages [#-related-pages] - [Copy Tracking](/docs/copy-tracking): copy codes, licence codes and the Download Log. - [Leak Tracing](/docs/leak-tracing): upload a leaked file to read its marks. - [Takedown Notices](/docs/takedown-notices): ask a website to remove leaked copies.