Adobe Photoshop CS5 for Photographers - Martin Evening [201]
Layers
Layers play an essential role in all aspects of Photoshop work. Whether you are designing a Web page layout or editing a photograph, working with layers lets you keep the various elements in a design separate from each other. Layers also give you the opportunity to assemble an image using separate, discrete layers and have the fl exibility to make any edit changes you want at a later stage. You can also add as many new layers as you like to a document, up to a maximum limit of 8000 layers! The Photoshop layers feature has evolved in stages over the years and Photoshop CS2 onwards includes new ways for selecting multiple layers and linking them together. Also new to Photoshop CS5 is the ability to drag and drop a file to a Photoshop document and place it as a new layer (see pages 526–527). First let's look at managing layers and the different types you can have in a Photoshop document.
Layer basics
Layers can be copied from one file to another by using the move tool to drag and drop a layer (or a selection of layers) from one image to another. This step can also be assisted by the use of the key to ensure layers are positioned centered in the destination file. To duplicate a layer, drag the layer icon to the New Layer button and to rename a layer in Photoshop, simply double-click the layer name. To remove a layer, drag the layer icon to the Delete button in the Layers panel and to delete multiple layers, use a -click or -click to select the layers or layer groups you want to remove and then press the Delete button at the bottom of the Layers panel. There is also a Delete Hidden Layers command in both the Layers panel submenu and the Layer Delete submenu. In addition there is now a File Scripts menu item that can be used to delete all empty layers (see Figure 9.10).
Figure 9.10 This shows the File Scripts menu, where there is now a new script item called ‘Delete All Empty layers’.
Application frame windows
Note that when using the Application frame window environment you cannot drag and drop layers from one document to another (or from the Layers panel). You can only do so if the foreground image window is undocked from the Application window.
Image layers
The most common type of layer is an image layer, which is used to contain pixel information. New empty image layers can be created by clicking on the ‘Create new layer’ button in the Layers panel (Figure 9.14). They can also be created by copying the contents of a selection to create a new layer within the same document. To do this, choose Layer New Layer via Copy, or use the keyboard shortcut. This copies the selection contents, so that they become a new layer in register with the image below. Alternatively you can cut and copy the contents from a layer by choosing Layer New Layer via Cut or use the keyboard shortcut.
Shape layers
Shape layers is a catch-all term used to describe non-pixel layers where the layer is filled with a solid color and the outline is defined using either a vector or pixel layer mask. A shape layer is created whenever you add an object to an image using one of the shape tools, or draw a path using the Shape layer mode, or when you add a solid fill layer from the adjustment layer menu. Figure 9.11 shows an example of a shape layer that is basically a solid fill layer masked by a vector mask.
Figure 9.11 The pen tool and shape tools include a Shape layer mode button for creating shape layer objects defined by a vector path.
Text layers
Typefaces are essentially made up of vector data, which means that Text layers too are basically vector-based shape layers. When you select the type tool in Photoshop and click or drag with the tool and begin to enter text, a new text layer is added to the Layers panel. Text layers are symbolized with a capital ‘T’, and when you hit to confirm a text entry, the layer name displays the initial text for that layer, making it easier for you to identify the layer (see Figure 9.12). Note that you