Editing layered content

You can select or copy content in a layered PDF document using the Select tool or the Snapshot tool. You can edit content using a touch-up tool. These tools recognize and select any content that is visible, regardless of whether the content is on a selected layer.

If the content that you edit or delete is associated with one layer, the content of the layer reflects the change. If the content that you edit or delete is associated with more than one layer, the content in all the layers reflects the change. For example, if you want to change a title and byline that appear on the same line on the first page of a document, and the title and byline are on two different visible layers, editing the content on one layer changes the content on both layers.

You can add content, such as review comments, stamps, or form fields, to layered documents just as you would to any other PDF document. However, the content is not added to a specific layer, even if that layer is selected when the content is added. Rather, the content is added to the entire document.

You can use the Create PDF From Multiple Files command to combine Adobe PDF documents that contain layers. The layers for each document are grouped under a separate heading in the Layers panel of the navigation pane. You expand and collapse the group by clicking the icon in the title bar for the group.

Source - Adobe

OCR Abobe Acrobat 9

How To Split and Merge

Merge or flatten layers

Merged layers acquire the properties of the layer into which they are merged (the target layer). Flattening PDF layers hides any content that is not visible when the flattening operation is executed and consolidates all layers.

Important: You cannot undo either a merging or a flattening operation.

Merge layers

1. Click the Layers button, and select Merge Layers from the Options menu.
2. In the left pane (Layers To Be Merged), select one or more layers to be merged. Ctrl/Command-click to select multiple layers, and click Add. Click Add All to merge all layers.
3. To remove a layer from the center panel, select the layer or layers. Ctrl/Command-click to select multiple layers. When your selection is complete, click Remove.
4. In the right pane (Layer To Be Merged Into), select the layer into which to merge the selected layers, and click OK.

Flatten layers

Click the Layers button, and select Flatten Layers from the Options menu.

Source：Adobe

Add layer navigation

You can add links and destinations to layers, allowing you to change the view of a document when the user clicks a bookmark or link.

Note: In general, changes to layer visibility made using the eye icon in the Layers panel are not recorded in the Navigation toolbar.

Associate layer visibility with bookmarks

1. Set the required layer properties, visibility, and magnification level for the target PDF layer in the document pane.
2. Click the Bookmarks button, and choose New Bookmark from the Options menu.
3. Select the new bookmark, and choose Properties from the Options menu.
4. In the Bookmark Properties dialog box, click the Actions tab.
5. For Select Action, choose Set Layer Visibility, click Add, and then click OK.
6. Select the bookmark label in the Bookmarks panel, and name the bookmark.

Associate layer visibility with a link destination

1. Set the required layer properties for the destination in the document pane.
2. Choose View > Navigation Panels > Destinations.

   The Destination panel appears in a floating panel. You can add it to the other panels by dragging it to the navigation pane. If the panel is collapsed, click the Destinations button to expand it.

3. Click the Create New Destination button or select New Destination from the Options menu, and name the destination.
4. Select the Link tool , and drag in the document pane to create a link. (Because content is added to all layers, it doesn’t matter that you are apparently creating the link on the target layer. The link works from any layer.)
5. In the Create Link dialog box, select Custom Link and click Next.
6. Click the Appearance tab in the Link Properties dialog box, and set the appearance of the link.
7. Click the Actions tab in the Link Properties dialog box, choose Set Layer Visibility, and click Add.
8. Close the dialog boxes.
   
   You can test the link by changing the layer settings, selecting the Hand tool, and clicking the link.

Source: Adobe