1 Layers About PDF layers You can view, navigate, and print layered content in PDFs created from applications such as InDesign, AutoCAD, and Visio. You can control the display of layers using the default and initial state settings. For example, you can hide a layer containing a copyright notice whenever a document is displayed on screen, while ensuring that the layer always prints. You can rename, flatten, and merge layers, change the properties of layers, and add actions to layers. You can also rearrange layers, import layers from image files and other PDFs, and lock layers to prevent them from being hidden. Acrobat does not allow you to author layers that change visibility according to the zoom level. However, you can highlight a portion of a layer that is especially important by creating a bookmark that magnifies or hides the layer using page actions. You can also add links that let users click a visible or invisible link to navigate to or zoom in on a layer. To retain layers when you convert InDesign CS documents to PDF, make sure that Compatibility is set to Acrobat 6.0 (PDF 1.5) or higher. Additionally, make sure that Create Acrobat Layers is selected in the Export Adobe PDF dialog box. Show or hide layers Information can be stored on different layers of a PDF. The layers that appear in the PDF are based on the layers created in the original application. Use the Layers panel to examine layers and show or hide the content associated with each layer. Items on locked layers cannot be hidden. Some layers may be organized into nested groups with a parent layer. Other layers may be in groups with no parent layer. Note: A Lock icon in the Layers panel indicates that a layer is for information only. Locked layers can be created from AutoCAD and Visio files. Use the Layer Properties dialog box to change the visibility of a locked layer. A B C D E Layers panel A. Eye icon indicates a displayed layer B. Locked layer C. Hidden layer D. Nested layer group E. Layer group 1 Choose View > Navigation Panels > Layers. 2 To hide a layer, click the eye icon. To show a hidden layer, click the empty box. (A layer is visible when the eye icon is present, and hidden when the eye icon is absent. This setting temporarily overrides the settings in the Layer Properties dialog box.) Note: In a nested layer group, if the parent layer is hidden, the nested layers are automatically hidden as well. If the parent layer is visible, nested layers can be made visible or hidden.
2 3 From the options menu, choose one of the following: List Layers For All Pages Shows every layer across every page of the document. List Layers For Visible Pages Shows layers only on the currently visible pages. Reset To Initial Visibility Resets layers to their default state. Apply Print Overrides Displays layers according to the Print settings in the Layer Properties dialog box (Prints When Visible, Never Prints, Always Prints). Apply Export Overrides Displays layers according to the Export settings in the Layer Properties dialog box (Exports When Visible, Never Exports, Always Exports). Apply Layer Overrides Displays all layers. This option affects all optional content in the PDF, even layers that are not listed in the Layers panel. All layers are visible, regardless of the settings in the Layer Properties dialog box. You cannot change layer visibility using the eye icon until you deselect this command. When you edit layer properties in the Layer Properties dialog box, changes are not effective until you choose Reset To Initial Visibility in the options menu. (Changes to the layer name are the exception; they are effective immediately.) Note: You cannot save the view of a layered PDF by using the eye icon in the Layers panel to show and hide layers. When you save the file, the visibility of the layers automatically reverts to the initial visibility state. To save a different view of a layered PDF, you must change the default state of the layers in the Layer Properties dialog box. Edit layer properties You can combine the default state setting, the visibility setting, and the print setting to control when a layer is visible and when it prints. If a layer contains a watermark, for example, you may want the layer to not show on-screen but always to print and always to export to other applications. In this case you can set the default state to on, the initial visibility to never visible (the image doesn t show on-screen), and the initial print and initial export states to always print and always export. The layer need not be listed in the Layers panel, since all the state changes are handled automatically. Note: The settings in the Layer Properties dialog box take effect only if Allow Layer State To Be Set By User Information is selected in the Documents preferences. If it is not selected, Layer Properties dialog box settings, other than Layer Name and Default State, are ignored. 1 Click the Layers button in the navigation pane. 2 Select a layer, and choose Layer Properties from the options menu. 3 In the Layer Properties dialog box, edit the layer name or any of the following properties, and then click OK: Intent Select View to allow the layer to be turned on or off, or select Reference to keep the layer on at all times and permit editing of the properties. When the Reference Intent option is selected, the layer appears in italics. Default State Defines the initial visibility state of the layer when a document is first opened or when the initial visibility is reset. The eye icons for layers are initially shown or hidden based on this value. For example, if this value is set to off, the eye icon for a layer is hidden when the document is first opened or when Reset To Initial Visibility is chosen from the options menu. Visibility Defines the on-screen visibility of the PDF layer. You can show a layer when the document is opened, you can hide a layer when the document is opened, or you can let the default state determine whether a layer is shown or hidden when the document is opened. Print Determines whether a layer will print. Export Determines whether the layer appears in the resulting document when the PDF file is exported to an application or file format that supports layers.
3 Any additional properties that the creator of the layered PDF has associated with a specific layer are shown in the box at the bottom of the Layer Properties dialog box. Reorder layers You can reorder individual layers in the Layers pane. This action is useful if you want to change the order of layers in the list, or move a layer from one layer group to another. Note: You cannot reorder locked layers, and you cannot reorder layers in nested layer groups. 1 In the Layers navigation panel, select a layer. 2 While holding down the Alt key, drag the layer to the new location. Delete an empty layer group In the Layers navigation panel, select an empty layer and press Delete. 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 Destinations 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 Choose 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.
4 You can test the link by changing the layer settings, selecting the Hand tool, and clicking the link. Import layers You can import layers from a PDF or image file into a target PDF. Supported image file formats are BMP, GIF, JPEG, JPEG 2000, PCX, PNG, and TIFF. 1 Click the Layers button in the navigation pane. 2 Choose Import As Layer from the options menu. 3 In the Import As Layer dialog box, click Browse and locate the file to import. If the source file is a multipage document, enter the page number you want to import in Page Number. If the target file is a multipage document, specify the Target Page Number in the Preview section of the dialog box. 4 Select one of the following import options: Create New Layer Creates a single, separate layer from the source document. Enter a name for the new layer. Add To Group Specifies the existing layer group in which to add the imported layer. This option is available only when the target PDF contains one or more existing layer groups, and when Create New Layer is selected. Add To Existing Layer Adds the content from the source document to an existing layer in the target document. Select a layer from your target document. The imported content will have the same layer properties as the existing layer in the target document. This option is available only when the target document contains layers. Copy Layers From Source Imports the layers from the source document. This option is available only when the source document contains layers. 5 Adjust the Position and Appearance settings as needed, and then click OK. 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 Layers To Be Merged pane, select one or more layers, and click Add. 3 To remove a layer from the center panel, select one or more layers, and click Remove. 4 In the Target Layer To Merge Into pane, select the layer into which to merge the selected layers. Flatten layers Click the Layers button, and select Flatten Layers from the options menu. Editing layered content You can select or copy content in a layered PDF document using the Select tool or the Snapshot tool. (In Reader, the PDF must include usage rights.) In Acrobat, you can edit content using a touchup tool. These tools recognize and select any content that is visible, regardless of whether the content is on a selected layer.
5 In Acrobat, 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. In Acrobat, you can use the Merge Files Into A Single PDF command to combine 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.