Each document contains a default layer, Layer 1, which contains all your objects until you create and select a new layer. Objects on the default layer ‚ and any other layer for that matter ‚ follow the standard stacking order of InDesign. (The first object you create is the backmost, the last one you create is the frontmost, and all the other objects fall somewhere in between. See Chapter 12 for complete information about stacking order.)
Like the clear plastic overlays, the order of the layers also affects the stacking order of the objects. Objects on the bottom layer are behind other objects, and objects on the top layer are in front of other objects. In Figure 6-1, the "Background Images" layer toward the bottom of the list contains the business card's standard graphics and the main text. Two additional layers contain different sets of contact information, in separate text frames , for different people.
Although layers are often compared to plastic overlays, there's one big difference: Layers are not specific to individual pages. Each layer encompasses the entire document, which doesn't make much difference when you're working on a 1-page ad but makes a significant difference when it comes to a 16-page newsletter. When you create layers and place objects on them, it's important that your strategy considers all the pages in the document.
The Layers pane (Window ‚ Layers, or F7) is your gateway to creating and manipulating layers (see Figure 6-2). As with other panes, when Show Tool Tips is checked in the General pane of the Preferences dialog box (choose InDesign ‚ Preferences on the Mac or Edit ‚ Preferences in Windows, or press z +K or Ctrl+K), you can learn what controls do by pointing at them. If you know what the controls do, you can intuit a great deal of how to work with layers.
The layers feature is one that you can honestly ignore. If you never looked at the Layers pane, you could continue to do your work in InDesign. But take a look at the possibilities and see if they fit into your workflow. In the long run, if you use layers you'll save time and prevent mistakes that can result when you need to track changes across multiple documents.
Say you've created an ad with the same copy in it but a different headline and image for each city the ad runs in. You can place the boilerplate information on one layer and the information that changes on other layers. If any of the boilerplate information changes, you only need to change it once. To print different versions of the ad, you control which layers print.
You might use layers in the following situations:
A project with a high-resolution background image, such as a texture, that takes a long time to redraw . You can hide that layer while designing other elements, then show it occasionally to see how it works with the rest of the design.
A document that you need to produce in several versions ‚ for example, a produce ad with different prices for different cities or a clothing catalog featuring different coats depending on the area's climate. You can place the content that changes on separate layers, then print the layers you need.
A project that includes objects you don't want to print. If you want to suppress printout of objects for any reason, the only way you can do this is to place them on a layer and hide it. You might have a layer that's used for nothing but adding editorial and design comments, which is deleted when the document is final.
A publication that is translated into several languages. Depending on the layout, you can place all the common objects on one layer, then create a different layer for each language's text. Changes to the common objects only need to happen once ‚ unlike if you created copies of the original document and flowed the translated text into the copies.
To experiment with different layouts of the same document. Yodifferent options to your supervisor or client. This strategy lets you use common elements, such as the logo and legal information, in several versions of the same design.
A complex design that contains many overlapping objects, text wraps, and grouped objects. Say the background of a page consists of a checkerboard pattern made up of filled, rectangular frames. You don't want to accidentally select the blocks while you're working with other objects. If you isolate complex objects on their own layer, you can show only that layer to work on it, hide that layer to concentrate on other layers, lock the layer so objects can't be selected, and otherwise manipulate the layer.
To create bulletproof templates. Locked layers are a great way to decrease the possibility of items in a template being moved or deleted. Move all the objects you don't want moved or deleted on a layer and lock it. Although a layer can be unlocked, it will keep the people who use the template from accidentally moving or removing anything too quickly.
When determining whether objects should go on a layer, remember that layers are document-wide and not page-specific.