Layers

Unlike in Photoshop, where it is common to have dozens of layers, InDesign documents typically have few layers. Some users even get by with the one default layer with the inspired name “Layer 1.” They can do so because each item on a spread is merely content in a layer, rather than a layer itself, as it would be in Photoshop. Commands like Object > Arrange > Send to Back give us a way to control stacking order and position items visually below or behind others. But as a document becomes more complex, layers give us greater control, and not just for stacking, although that’s a fine place to start.

Stacking Order

To the left of a layer’s name in the Layers panel is a small arrow that, when clicked, shows the items populating that layer on the current spread. If the listed items overlap on the spread, the topmost object is topmost in the Layers panel, too. When an object is selected, its horizontal position (X) and vertical position (Y) are shown in the Control panel. Dragging an item’s name below another’s will set that object’s Z order (stacking order) to be below the other object’s.

To the left of the disclosure arrow is a small color bar, which shows the color associated with objects on that layer. Frame edges and several other nonprinting attributes will be displayed in this color so you can know what layer the object inhabits. If an object is selected, the small square to the right of its layer’s name will fill with that color. That square is then a proxy for the object and can be dragged to other layers (if you have any), even without expanding them.

If a layer is expanded so you can see its contents, another square will be filled with that color next to the object that is selected in the layout. Those small squares can also be clicked to select objects. This is wonderful if one object is difficult to click on in the layout or is part of a group (whose content can also be “disclosed” with a small arrow to the left of the group). I sometimes right-click an object’s name in the Layers panel and choose Select and Fit Item to both select and center the item on my screen.

Creating Layers

The first item in the Layers panel menu is New Layer…. I like to use this method for creating layers because it encourages me to both name the layer and choose a color for its content’s edges. An existing layer’s name can be changed by either double-clicking the current one or right-clicking it and choosing Layer Options. Below, I changed the name of the default layer to “images” and its color from light blue to blue. I then created a new layer with the name “textual content” and chose red as its color.

Moving Content Between Layers

To move content (in this case, text frames) from the “images” layer to the new one, I first selected the frames with my Selection tool, which made the proxy next to the “images” layer blue. (When you hover a cursor above a proxy, you’ll see the tool tip above. I followed those instructions!) I then dragged the blue proxy to the right of the “textual content” layer, and the frames I had selected moved to that layer.

Reordering Layers

Dragging a layer by its name above or below others puts its content above or below the content in the other layers. The example above is not an arbitrary one; for esoteric output reasons, I often want images (especially those with transparent bits) to be below text. By having a layer for them, I’m encouraged to put them there.

You may also wish to ensure that some items, like page numbers or running headers, are never obscured, even by full-bleed images. Having those elements on a layer at the top of the stack could be a nice way to arrange that.

Segregating Types of Content

Segregating content into distinct layers allows us to do some pretty cool things. Layers can be set to be nonprinting (double-click a layer’s name to see that option). Why would you do that (besides as a prank on colleagues)? You may wish to leave notes or instructions in a template, for example, without the risk of their being output.

Instead of making a layer nonprinting, you may wish to protect its content from accidental edits. To accomplish that, click to the right of the small eye icon (eye-con?) to lock the layer. If a layer is expanded to show its content, you may lock individual items instead.

Speaking of that eye-con, it controls a layer’s visibility. Consider a multilingual document in which only one language at a time is to be output. You may have one InDesign file that you can export as a PDF, but with only some layers visible each time. Another example would be a textbook; the teacher’s edition would have content not visible in the student edition.

I sometimes put my ruler guides on a layer of their own so I can hide them without hiding my margin or column guides. The shortcut ⌘-;/Ctrl-; (semicolon) toggles the visibility of all guides. To easily select all guides, use the shortcut ⌘-option-G/Ctrl-Alt-G. You can then drag the proxy to another layer, which can be either locked (locking the guides) or hidden (hiding them). Guides are usually created on a master page via Layout > Create Guides…. This presents no problem, as layers are available across all pages, and hiding a layer hides its content on all pages. If that layer is above all the others, its content, even master page content, will be above all the rest.

Deleting Layers

The safest command for deleting layers is found in the Layers panel menu: Delete Unused Layers. This is something I do when a project is finished. If you highlight a layer and click the little trash can at the bottom of the Layers panel, you’ll be warned if there’s content on it—a good thing, as that content will get deleted with the layer. If you feel that you have too many layers, a better solution is to merge them. Highlight two or more and then choose Merge Layers from the Layers panel menu.