# Visible vs invisible PDF watermarks: how each protects your files (/guides/visible-vs-invisible-watermarks)

Visible stamps can discourage sharing by putting the buyer's details on the page. Hidden marks give you another way to identify a copy if its stamp is removed. Both depend on the mark surviving; neither makes a PDF impossible to share.

So the short answer is to use both. The rest of this guide explains how each one gets defeated, what Imprint's versions do, and how to set them up for the kind of PDF you sell.

## What a visible watermark does [#what-a-visible-watermark-does]

A visible watermark, or stamp, is text printed onto the pages. It's usually the buyer's name or email, sometimes with an order number, a code or a line like "Licensed to Jane Doe for personal use".

**It deters.** It works on the casual sharer, the buyer who would forward the file to a friend or drop it into a Facebook group without a second thought. With their name on every page, the file isn't anonymous anymore, and they know it.

**It traces, if it survives.** A stamp left intact tells you whose copy it was at a glance, with no tools.

**It has costs.** It takes up room on the page and can clash with your design. Names and email addresses expose customer details if the file leaks. A copy code lets you look up the download without printing those details on the page.

## How visible watermarks get removed [#how-visible-watermarks-get-removed]

A visible stamp is the first thing a leaker deals with, because it's in plain sight. The usual methods:

- **Cropping.** A stamp alone in the bottom margin can be cut off every page in a few clicks.
- **Covering.** A white rectangle drawn over the stamp hides it, and on a plain background it's hard to spot.
- **Editing.** A stamp added as text or as a separate layer can sometimes be selected and deleted in a PDF editor.
- **Deleting pages.** A stamp on the first page only disappears with that page.
- **Converting.** Turning the PDF into images, or into an editable format and back, gives the leaker a chance to clean up every page.

You can make each of these harder. Stamp every page, so deleting one doesn't help. Place the stamp where a crop would cut into your content. Add a short copy code next to the name, so removing the name alone isn't enough. And keep the stamp small and semi-transparent, so it reads as part of the page instead of an obvious target.

## What an invisible watermark does [#what-an-invisible-watermark-does]

An invisible watermark is a code hidden in the file that identifies the copy, in a place the reader doesn't see. In PDFs, the common kinds are:

- **Document properties.** The code is saved in the file's metadata, next to the title and author.
- **Hidden text.** The code is on the page itself, in text too small or faint to see when reading or printing.

Some systems go further and encode information in tiny changes to letter spacing or images.

**It can help trace a copy.** A hidden mark may survive an edit that removes the visible stamp. If you can read the code and match it to your records, it can lead you to the order.

**It doesn't deter on its own.** A buyer can't be put off by a mark they don't know about. You can close that gap without giving anything away: say on your product page, or in the stamp itself, that each copy carries hidden identifying marks. Buyers then know the file is traceable, but not where the marks are.

## How invisible watermarks get defeated [#how-invisible-watermarks-get-defeated]

Hidden marks can be overlooked, but they can also be removed deliberately or lost during conversion:

- **Printing to images, scanning, photos and screenshots** remove hidden text and document properties, because only what's visible on the page survives.
- **Cropping the margins** can hide or remove hidden text, depending on how the tool crops the file.
- **Re-saving in some PDF tools** clears the document properties.
- **Comparing copies.** Someone who has copies from two different buyers can compare the files and see what differs between them.

Using several marks gives you more ways to identify a copy. Some conversions remove several marks at once, so tracing is still not guaranteed.

## The QR code: a visible mark that survives printing [#the-qr-code-a-visible-mark-that-survives-printing]

A QR code holds a copy code in a visible square on the page. Like a visible text stamp, it can survive printing, scanning, photos and screenshots if it remains readable. Imprint can read its QR codes automatically, which makes them useful for printed patterns and sheet music.

Its weakness is that it can be seen, so it can be cropped off or covered, and it takes up a little space.

## Side by side [#side-by-side]

| | Visible stamp | Hidden text | Document properties | QR code |
| :--- | :--- | :--- | :--- | :--- |
| Makes buyers think twice | Yes | Only if you tell them | Only if you tell them | If they notice it |
| Can identify a copy or order | If readable | If readable | If retained | If readable |
| Survives printing and scanning | Yes, if not removed | No | No | Yes, if readable |
| Survives cropping | Depends on placement and tool | Depends on placement and tool | Unless properties are also removed | Only if still visible and readable |
| Survives re-saving in other tools | Depends on the tool | Depends on the tool | Depends on the tool | Depends on the tool |
| Changes how the page looks | Yes | No | No | Slightly |

## What Imprint's stamp and tracing marks do [#what-imprints-stamp-and-tracing-marks-do]

Imprint adds both kinds at the moment of download, so every copy is different.

- **The visible stamp (every plan).** On the Free plan, it's the customer's email, centered at the bottom of the page in small gray text. On Basic and up, you write the text yourself, using the customer's name, email, order number, company, up to 5 custom fields from checkout or a product form, and the copy and licence codes. You also choose one of 9 positions, the font size, color and opacity. On every plan you can stamp every page or the first page only.
- **Copy codes (Basic and up).** Each download gets its own code, which you can add to the stamp. The order page lists every download with its code, and **Find Order by Code** opens the order behind any code.
- **Tracing marks (Premium).** The copy code goes into micro-text in the bottom-left margin of every page, and the copy code and the order's licence code go into the document properties. An optional QR code of about 1 cm holds the copy code, in the corner you choose, on a small white square. The marks are added even with the visible watermark off, and they go on every page even when the stamp is on the first page only.
- **Leak tracing (Premium).** Upload a copy you found, and [Imprint looks for surviving marks and customer details](/leak-tracing). It shows any matching order and, when a copy code is found, the download, with a confidence level. A match doesn't prove who shared the file.

Two limits to know: marks only go into copies downloaded after you switch them on, and a PDF with a permissions password is sent unchanged, without marks, when no watermark applies to it. The [PDF stamping page](/pdf-stamping) and the [Watermark Settings docs](/docs/watermark-settings) cover the stamp, and the [tracing marks docs](/docs/tracing-marks) explain where each mark goes and what can remove it.

## Which to use, by product type [#which-to-use-by-product-type]

For almost every PDF, the answer is a visible stamp plus hidden marks. What changes from product to product is how much stamp the pages can take.

### Ebooks and guides [#ebooks-and-guides]

Stamp every page with the buyer's name and a copy code, small, in the footer. Add hidden marks. If your readers mostly read on screen, the QR code matters less, but it costs little in an empty corner.

### Sewing, knitting and crochet patterns [#sewing-knitting-and-crochet-patterns]

Patterns get printed, often at a set scale, so the stamp must never cover pattern pieces or the test square. Put one short line in a margin on every page, and check the printed result before you sell. Turn on the QR code, since printed patterns can end up shared as photos and scans and the QR code is the mark that survives that. Pick a corner your pattern pieces leave empty, because the QR code's white square covers whatever is underneath.

### Sheet music [#sheet-music]

A page of music has little spare room, and musicians print and photocopy their parts. Keep the stamp to one short line, such as the name and copy code, at the bottom of every page, and turn on the QR code so photocopies stay traceable.

### Planners and printables [#planners-and-printables]

A digital planner with hundreds of pages and a stamp on every one can get in the buyer's way, especially once it's imported into a note-taking app. Stamp the first page only and let hidden marks cover the rest. Imprint's tracing marks still go on every page when the stamp is on the first page only. For short printables, a small footer stamp on every page is usually fine.

### Templates and worksheets [#templates-and-worksheets]

Buyers fill these in or reuse them, so the stamp mustn't land where they write. A footer line like `Licensed to {name} for personal use`, plus hidden marks, covers it.

### Courses, workbooks and business reports [#courses-workbooks-and-business-reports]

Stamp every page with the buyer's name and copy code. For a report licensed to a company, stamp the company name too: Imprint's `{company}` variable reads it from the order's billing or shipping address.

## Where to go from here [#where-to-go-from-here]

Start with a visible stamp that includes a copy code, then add hidden marks and a QR code when you're ready to trace leaks that get past the stamp.

For the rest of the setup, including download links, limits and a launch checklist, see [How to sell PDFs on Shopify and limit sharing](/guides/sell-pdfs-on-shopify). If a copy is already out, [How to find out who leaked your PDF](/guides/find-who-leaked-your-pdf) shows how to read these marks and what to do next.