A QuarkXPress layer is like a clear overlay that covers every page in a layout. You can put almost anything on a layer, including picture boxes, text boxes, lines, tables, interactive objects, and any other kind of QuarkXPress item.

Layers can be useful in many different ways:

• You can put different translations of a document on different layers, and thus store all language versions of the document in the same layout. When you print the layout, you can hide all of the layers except the one that contains the language you want.
• You can put different versions of a design on different layers, so that you can easily switch back and forth among variations on the design theme when showing a design to a client.
• You can use layer locking to prevent accidental changes to layers containing page elements that should not be altered. For example, if you’re going to be printing on stock that is preprinted with a letterhead and background graphic, you can include that letterhead and background graphic in a layer so that you can see what the finished printed piece will look like, and then you can lock that layer and omit it from printing.

If you have used image-editing applications such as Adobe Photoshop, you may already be familiar with the concept of layers. However, layers have some implications in QuarkXPress layouts that they do not have in image editing:

• Even if a front layer is showing, you can “click through” any empty portions of that layer and select items on underlying layers, without having to manually change the active layer.
• Each layer exists on every page in a QuarkXPress layout, rather than being specific to a page or spread. This makes it easy to control the appearance of every page in a long layout.
• Text in a rear layer can run around objects in a front layer.