Working with layered images

There are many advantages to working with layered images. You can quickly select, hide, duplicate, lock, and change the appearance of images using layers.

Selecting layers

If an image has multiple layers, you must choose which layer you want to work on. Any changes you make to the image affect only the active layer. You select a layer to make it active, and only one layer can be active at a time. The name of the active layer appears in the title bar of the document window, and a paintbrush icon appears next to the layer in the Layers palette.

If you don’t see the desired results when using a tool or applying a command, you may not have the correct layer selected. Check the Layers palette to make sure that you’re

working on the desired layer.

To select a layer:

Do one of the following:

•Click a layer in the Layers palette.

•Select the move tool, right-click (Windows) or Control-click (Mac OS) in the image, and choose a layer from the context menu.The context menu lists all the layers that contain pixels under the current pointer location.

You can also select layers interactively as you use the move tool. If Auto Select Layer is selected in the Move tool options, the topmost layer containing pixels under the cursor will be selected. (See “Moving selections and layers within an image” on page 167.)

Displaying the contents of layers

You can use the Layers palette to selectively hide and display the contents of layers, layer sets, and layer effects. You can also specify how transparent areas are displayed in the image.

To change the visibility of a layer, layer set, or layer effect:

Do one of the following:

•In the Layers palette, click the eye icon next to a layer, layer set, or layer effect to hide its content in the document window. Click in the column again to redisplay the content.

•Alt-click (Windows) or Option-click (Mac OS) an eye icon to display only the content for that layer or layer set. Alt/Option-click in the eye column again to redisplay all content.

•Drag through the eye column to change the visibility of multiple items in the Layers palette.

Note: Only visible layers are printed.

To change the display of transparency:

1 Do one of the following:

•(Photoshop) In Windows and Mac OS 9.x, choose Edit > Preferences > Transparency & Gamut; in Mac OS X, choose Photoshop > Preferences > Transparency & Gamut.

•(ImageReady) In Windows and Mac OS 9.x, choose Edit > Preference > Transparency; in Mac OS X, choose ImageReady > Preferences > Transparency.

2Choose a size and color for the transparency checkerboard, or choose None for Grid Size to hide the transparency checkerboard.

3(Photoshop) Select Use Video Alpha to enable Photoshop to send transparency information to your computer’s video board. This option requires hardware support—make sure that your computer’s video board allows images to be overlaid on top of a live video signal.

4Click OK.

Duplicating layers

Duplicating layers is an easy way to copy content within an image or between images. When duplicating layers between images, keep in mind that the layer’s content will appear smaller or larger if it is copied to a file with different resolution. (See “About image size and resolution” on page 62.)

To duplicate a layer or layer set within an image:

1Select a layer or layer set in the Layers palette.

2Do one of the following:

•Drag the layer to the New Layer button , or drag the layer set to the New Layer Set button .

•Choose Duplicate Layer or Duplicate Layer Set from the Layers menu or the Layers palette menu. In Photoshop, enter a name for the layer or layer set, and click OK.

•(Photoshop) Press Alt (Windows) or Option (Mac OS), and drag the layer or layer set to the New Layer button or the New Layer Set button. Enter a name for the layer or layer set, and click OK.

To duplicate a layer or layer set between images:

1Open the source and destination images.

2In the Layers palette of the source image, select a layer or layer set.

3Do one of the following:

•Drag the layer or layer set from the Layers palette into the destination image.

•Select the move tool , and drag from the source image to the destination image. The duplicate layer or layer set appears above the active layer in the Layers palette of the destination image. Shift-drag to position the image content in the same location it occupied in the source image (if the source and destination images have the same pixel dimensions) or at the center of the document window (if the source and destination images have different pixel dimensions).

•(Photoshop) Choose Duplicate Layer or Duplicate Layer Set from the Layers menu or the Layers palette menu. Choose the destination document from the Document pop-up menu, and click OK.

•Choose Select > All to select all of the pixels on the layer, and choose Edit > Copy. Then choose Edit > Paste in the destination image.

To create a new document from a layer or layer set (Photoshop):

1Select a layer or layer set in the Layers palette.

2Choose Duplicate Layer or Duplicate Layer Set from the Layers menu or the Layers palette menu.

3Choose New from the document pop-up menu, and click OK.

Changing the stacking order of layers

The stacking order in the Layers palette determines whether the content of a layer or layer set appears in front of or behind other elements in the image.

To change the order of layers and layer sets:

Do one of the following:

•Drag the layer or layer set up or down in the Layers palette. Release the mouse button when the highlighted line appears where you want to place the layer or layer set.

•To move a layer into a layer set, drag a layer to the layer set folder . The layer is placed at the bottom of the layer set.

•Select a layer or layer set, choose Layer > Arrange, and choose a command from the submenu. If the selected item is in a layer set, the command applies to the stacking order within the layer set. If the selected item is not in a layer set, the command applies to the stacking order within the Layers palette.

Note: By definition, the background layer is always at the bottom of the stacking order. Therefore, the Send to Back command places the selected item directly above the background layer. (See “About the background layer” on page 285.)

Linking layers

By linking two or more layers or layer sets, you can move their contents together. You can also copy, paste, align, merge, apply transformations to, and create clipping groups from linked layers.

To link layers:

1Select a layer or layer set in the Layers palette.

2Click in the column immediately to the left of any layers you want to link to the selected layer. A link icon appears in the column.

To unlink layers:

In the Layers palette, click the link icons to remove them.

Repositioning the contents of layers

You can reposition the contents of layers and layer sets using the move tool. (See “Moving selections and layers within an image” on page 167.) You can also align and distribute the contents of layers using commands in the Layers menu.

Note: The align and distribute commands affect only those layers that contain pixels of greater than 50% opacity.

To align the contents of layers: 1 Do one of the following:

• To align the content of a layer to a selection border, make a selection in the image.Then select a layer in the Layers palette.

• To align the contents of multiple layers to a selection border, make a selection in the image. Then link together the layers you want to align in the Layers palette. (See “Linking layers” on page 289.)

• To align the contents of layers to the content of the active layer, link the layers you want to align to the active layer. (See “Linking layers” on page 289.)

2 Choose Layer > Align Linked or Layer > Align To Selection, and choose a command from the submenu:

•Top Edges to align the top pixel on the linked layers to the top pixel on the active layer or the top edge of the selection border.

•Vertical Centers to align the vertical center pixel on the linked layers to the vertical center pixel on the active layer or the vertical center of the selection border.

•Bottom Edges to align the bottom pixel on the linked layers to the bottom pixel on the active layer or the bottom edge of the selection border.

•Left Edges to align the left pixel on the linked layers to the left pixel on the active layer or the left edge of the selection border.

•Horizontal Centers to align the horizontal center pixel on the linked layers to the horizontal center pixel on the active layer or the horizontal center of the selection border.

•Right Edges to align the right pixel on the linked layers to the right pixel on the active layer or the right edge of the selection border.

To distribute layers:

1In the Layers palette, link three or more layers. (See “Linking layers” on page 289.)

2Choose Layer > Distribute Linked, and choose an option from the submenu:

•Top Edges to space the linked layers evenly starting from the top pixel on each layer.

•Vertical Centers to space the linked layers evenly starting from the vertical center pixel on each layer.

•Bottom Edges to space the linked layers evenly starting from the bottom pixel on each layer.

•Left Edges to space the linked layers evenly starting from the left pixel on each layer.

•Horizontal Centers to space the linked layers evenly starting from the horizontal center pixel on each layer.

•Right Edges to space the linked layers evenly starting from the right pixel on each layer.

Locking layers

You can fully or partially lock layers to protect their contents. When a layer is locked, a lock icon displays to the right of the layer name. The lock icon is solid when the layer is fully locked; it is hollow when the layer is partially locked.