#  `modify_layers`

Modify state, merge, or strip specific layers
## Usage
> pdftl `<input>` `modify_layers` `[action]` `[target]...` `output` `<output>` `[<option>...]`

## Details
The `modify_layers` operation allows you to alter Optional Content Groups
(layers) in a PDF. You can permanently merge/strip them, or change their
default visibility and behavior.

The command reads a sequence of action-target pairs. If no target is provided
after an action, it defaults to affecting "all" layers.

### Available Actions

**Structural (Permanent):**
* `merge`: The visual content of the layer is permanently baked into the
  page. The layer is removed from the PDF's layer menu.
* `strip`: The visual content of the layer is completely deleted from the
  document, and the layer is removed from the PDF's layer menu.

**State & Behavior (Non-destructive):**
* `show` / `hide`: Sets the default visibility when the document is opened.
* `lock` / `unlock`: Prevents/allows the user from toggling the layer in viewers.
* `print` / `noprint`: Overrides behavior to force layer visibility ON or OFF when printing.
* `screen` / `noscreen`:
  Overrides behavior to force layer visibility ON or OFF on digital displays.

**Utility:**
* `keep`: Used primarily to exclude a specific layer when targeting "all" others.

*Note on State vs. Usage: Layer visibility on screen (`show`/`hide`) is independent
of its visibility when printing. Modifying a usage state (like `noprint`) without
changing its base state will leave its on-screen visibility unchanged.*

### Target Specifications

* `name=<string>`: Sloppy match. Applies the action to **all** layers with this name.
* `id=<integer>`: Strict match. Applies the action to the exact underlying PDF object.
* `all`: Explicitly targets all layers.
* `<string>`: If no `key=` prefix is provided, it defaults to a `name=` match.
## Examples

> Strip ALL layers from the PDF.
```
pdftl in.pdf modify_layers strip output out.pdf
```

> Hide all layers by default, except 'Draft'.
```
pdftl in.pdf modify_layers hide all show name=Draft output out.pdf
```

> Prevent the 'Watermark' layer from showing up on paper.
```
pdftl in.pdf modify_layers noprint name=Watermark output out.pdf
```


**Tags**: layers, modify, merge, strip, visibility, print

*Source: pdftl.operations.modify_layers*

*Read online: [https://pdftl.readthedocs.io/en/stable/operations/modify_layers.html](https://pdftl.readthedocs.io/en/stable/operations/modify_layers.html)*

*Type: Operation*