9. Using Layers for Collage and More

In this chapter, you’ll learn how to create layers and manipulate them to build complex images.

Only one pixel can operate a given location within an image, and if you paste another pixel over the first one, the old one is gone—unless it’s on a layer of its own. Layers enable you to manipulate parts of an image as separate objects, just as you can shapes and type. With layers, you can keep your options open.

When you put an object on a layer, you can move it around later on. If you paste it on the Background layer, on the other hand, you’re stuck, because whatever was behind it is no longer there. With layers, you can restack and move the contents of your layers as many times as you want without deleting any image content.

Layers also give you the ability to combine colors of layered pixels to produce new colors, which doesn’t happen when you just paste stuff on the Background layer. By using blending modes such as Overlay, you can combine images for realistic effects. For example, you can add a picture to an image of a brick wall so that the wall’s surface texture shows through and the picture looks as though it’s painted on the wall (see Figure 9.1).

Figure 9.1. Using the Multiply blending mode makes the apple layer, created using the Shape tool and the Glass filter, appear to be painted on the brick wall.

Managing Layers

Most layer manipulation happens in the Layers panel, where you can see each layer listed in order from topmost to bottommost, with the Background layer (if there is one) at the bottom of the list and at the bottom of the stack. It’s here that you add and delete layers, change their stacking order, and click a layer to activate it so you can work on its contents.

Each entry in the Layers panel includes these elements:

• Thumbnail—This shows you what’s on each layer. Special thumbnails indicate type, fill, shape, and adjustment layers (see Figure 9.2).

Figure 9.2. The Layers panel packs a lot of information into a small space.

• Name—Double-click a layer’s name to enter a new name, or leave the default names if you prefer.

• Lock icon—This icon indicates that the layer has been locked using the Lock button at the top of the panel, so that the contents can’t be modified or moved.

• Visibility button—Click the eye to temporarily hide the layer; click the space where the eye should be to show the layer again.

To change how the Layers panel displays layers, choose Panel Options from the Layers panel menu. You can choose from three thumbnail sizes or choose to have no thumbnails at all, and you can set whether each layer’s thumbnail displays the entire layer or just the nontransparent objects on that layer.

Adding and Deleting Layers

When you’re working on a layer, any edits you make or adjustments and filters you apply work only on that layer—the active layer—not on the entire picture. You can add content to a layer by painting on it, by filling and stroking selections, and by assigning layer styles to it. The Photoshop Elements Editor supports six different kinds of layers, each suited to a different purpose. Every image starts out with a Background layer, which can be blank, filled with the color you specified when creating the new image, or filled with a scanned image. In addition, you’ll use these layer types:

• Regular—Think of a normal transparent layer as similar to a sheet of transparency film or plastic wrap. You can place image content on it, but every part of the layer not occupied by that content is completely transparent, allowing whatever’s on the layers below to show through (see Figure 9.3).

Figure 9.3. The area around the blender is transparent, and some of the area within the blender is partially transparent, enabling the bricks to show through.

• Fill—These layers are filled with a single color, a gradient, or a pattern. You can’t paint on them or erase them, but each fill layer has a layer mask that you can paint on to hide parts of the fill.

• Adjustment—Like fill layers, these have layer masks that you can modify. Adjustment layers don’t contain colors or patterns. Rather, each contains an image adjustment, such as a hue change, that applies to all the layers below it.

• Type—Type layers are also not editable by painting or erasing; they contain only type characters. (Turn to Chapter 8, “Painting, Drawing, and Adding Type,” to learn more about creating type within images.)

• Shape—Using the shape tools creates shape layers that contain only the shapes you create. You can’t paint or erase on a shape layer, but you can return to it to edit the shapes as many times as you want. (Chapter 8 also covers creating and editing shapes.)

Type and shape layers are added automatically when you use the type or shape tools or when you drag objects into the image window from the Content panel. You work with the other kinds of layers using buttons on the Layers panel (see Figure 9.4). Click the Add Layer button at the bottom of the Layers panel to create a new, empty layer, or click the New Fill/Adjustment Layer button to make a fill layer or an adjustment layer. (See “Putting Image Adjustments on Layers,” later in this chapter, to learn more.)

Figure 9.4. Buttons on the Layers panel enable you to manipulate layers easily.

You can create new layers in several other ways. For one thing, any time you use the Paste command, a new layer is created to hold the contents of the Clipboard, whether you’re pasting copied or cut material from this image or another image. You can also take a shortcut to create new layers from parts of the current image. Just select the area you want to include on the new layer and choose either Via Copy or Via Cut from the New Layer submenu at the top of the Layer menu. If you choose Via Copy, the original pixels are left in place. If you choose Via Cut, they’re deleted, revealing either transparency or the Background color depending on whether the selection is on a regular layer or the Background layer.

You can also drag a layer to the New Layer button to duplicate it, or click it in the Layers panel and then choose the Duplicate Layer command from either the Layer menu or the Layers panel menu. When you use the Duplicate Layer command, you’ll be given the option of creating a new layer within the current document or using it as the basis for a completely new image (see Figure 9.5). Because Duplicate Layer works with the Background layer as well as other kinds of layers, you can use this as a quick way to create backup copies of an image that you’re about to modify heavily.

Figure 9.5. By choosing New and entering a name, I can copy the current layer to a completely new image file.

Turning the Background layer into a regular layer requires only that you double-click the layer’s entry in the Layers panel. It’s renamed Layer 0, although you can enter a different name in the Layer Options dialog if you like (see Figure 9.6), and it becomes a completely filled transparent layer. From this point on, if you use the Eraser tool on this layer, you’ll erase to transparency instead of to the background color.

Figure 9.6. When you double-click the Background layer, the Editor asks what name you’d like to assign to the new transparent layer.

Deleting layers is just as simple as creating them, and it works the same for any kind of layer. Drag a layer to the Delete Layer button (more familiar to most people as the Trash) at the bottom of the Layers panel, or click the layer and then click the Delete Layer button, to delete it.

Another way to delete layers is to combine them with other layers. This reduces the image’s file size without deleting any content. You can merge all the layers into the Background by choosing Flatten Image at the bottom of the Layer menu, or you can merge selectively using several different commands.

When one layer is selected, you can merge it with the layer below it by choosing Merge Down from the Layer menu, unless it’s linked with one or more other layers, in which case the Merge Down command changes to Merge Linked. Choosing this command combines all the linked layers, regardless of how many there are. If two or more layers are selected, on the other hand, the Merge command becomes Merge Layers, and it works on all the selected layers. Finally, the Merge Visible command is always available, and it works on any layer that’s not hidden. Press Alt while choosing Merge Visible to combine all the visible layers on the current layer without deleting the original layers (see Figure 9.7).

Figure 9.7. By pressing Alt as I choose Merge Visible, I can copy the contents of all layers to the current layer without deleting the original layers. Now I’ll be able to apply filters to the image as a whole.

Rearranging Layers

The order in which layers are stacked determines what shows and what doesn’t. You can reorder layers by clicking them into the Layers panel and dragging them up and down within the Layers panel. When a layer uses a blending mode other than Normal (see the next section, “Modifying Colors with Blending Modes”), changing its stacking order determines not just what shows in front of other objects but also what color it is, as well as the colors on layers below it. To reorder more than one layer at a time, Ctrl-click to select the layers you want to move, then drag them up or down (see Figure 9.8). With multiple layers selected, you can also choose Reverse from the Arrange submenu in the Layer menu to flip the stack around, moving the top layer to the bottom and so on.

Figure 9.8. The green Layer 1 has been moved from the bottom of the layer stack to the top.

Moving content on a layer, rather than the layer itself, is the job of the Move tool. Just select the layer, and then click and drag in the image window. Or select the layer and press the arrow keys on your keyboard to move the layer content one pixel at a time. Press Shift as you press the arrow keys to move the layer content 10 pixels. When you’re moving content by dragging, as opposed to using the arrow keys, press Shift as you drag to constrain movement in 45° increments: up, down, left, right, or halfway between those points.

To move more than one layer at a time, Ctrl-click to select the layers in the Layers panel and click the Link button at the bottom of the panel. Linked layers always move together; unlink them by clicking the Link button again to move them independently. When layers are linked, you can also copy, paste, and apply transformations to their combined contents simultaneously.

Transforming layer content means changing its shape or position in one of several ways. First, select the layers you want to transform, and then make sure the Move tool is active.

• To resize the layer content, drag any handle of the bounding box (see Figure 9.9). Press Shift as you drag a corner handle to retain the existing proportions.

Figure 9.9. Resizing layer content puts the layer in Transform mode, at which point you can perform a number of other transformations on it.

• To rotate the layer content, press Ctrl+T or resize the bounding box to enter Transform mode, and then click and drag outside of the bounding box. Press Shift as you drag if you want to constrain the rotation to 15° increments, and click a difference square on the reference point locator in the tool Options bar if you want to change the point around which the selection rotates.

• To distort the layer content, press Ctrl and drag any handle.

• To skew the layer content, press Ctrl+Shift and drag any side handle of the bounding box.

• To apply perspective to the layer content, press Ctrl+Alt+Shift and drag any corner handle.

When you’re happy with the layer content’s new shape, either press Enter or click the Commit button to apply the changes.

Because each layer forms a unit by itself, you can copy layers from one image to another without making a selection within the image window. Drag one or more layers from the Layers panel into another image window to copy them to that window, pressing Shift as you drag to make the new layer occupy the same relative position that it had in the original image or to move it to the center if the new image is a different size. If the two images do have different resolutions, you’ll find that the copied layers appear to be a different size relative to their new image than they were in the original image.

Modifying Layer Colors with Blending Modes

If you’ve already read Chapter 8, “Painting, Drawing, and Adding Type,” you know that painting tools can use blending modes—alternative ways of laying down color so that it blends with the existing colors in the image. Layers also use blending modes to determine how the colors on layers below combine with the colors on the active layer (see Figure 9.10). You can even combine these two venues for blending modes by using non-normal blending modes with tools on a layer that also uses a blending mode other than Normal. If that concept makes your head spin, you’re not alone. The best way to learn how blending modes work is simply to try them all out in different combinations. To refresh your memory of what the different blending modes are and what they’re supposed to accomplish, I’ve repeated the blending mode table from the previous chapter here (see Table 9.1).

Figure 9.10. The background pattern shows through the heart, but the colors combine to produce black lines because of the heart layer’s Linear Burn blending mode.

Table 9.1. Blending Modes

Hiding and Showing Layers

As you saw earlier in this chapter, clicking the eye-shaped visibility button next to a layer’s entry in the Layers panel hides that layer temporarily. The layer’s content is still there, and you can still move the layer up and down in the layer stack and even select its transparency mask by Ctrl-clicking the layer’s icon. You just can’t see it until you click again in the empty space where the visibility icon was, which makes it easier to work on the layers below it. If you want to hide all the layers except one, you can Alt-click the visibility icon next to the layer you want to view (see Figure 9.11).

Figure 9.11. The heart’s still there, you just can’t see it.

LET ME TRY IT

Building and Working with Layers

With layers, you can construct an image that’s infinitely more flexible than it otherwise would be. In this example, you can change the background, the filter applied to the photos, and the color and content of the type, all without affecting the rest of the image, because each element resides on its own layer.

1. Create a new blank image using the settings shown in Figure 9.12.
   

   Figure 9.12. This image will be large enough to print smoothly on a letter-sized page.

   

2. In the Layers panel (choose Layers from the Window menu if it’s not visible), click the New Fill or Adjustment Layer button and choose Gradient.
3. Choose one of the spectrum (rainbow) gradients from the drop-down panel in the Options bar, then set the Angle to about 170° and the Style to Linear and click OK.
4. Now add a type layer. Switch to the Type tool, change the foreground color to bright pink, and click at the bottom of the image window to enter the poster’s text (mine is shown in Figure 9.13). Change the type layer’s blending mode to Difference using the Mode menu at the top of the Layers panel.
   

   Figure 9.13. The Difference blending mode recolors the type depending on how its actual color combines with the different colors in the rainbow background.

   

5. Open two images showing different animals; I’m using a cat and a dog. In each, choose Magic Extractor from the Image menu and use the Magic Extractor to delete the background. (See the section “Deleting the Background” in Chapter 7, “Using Advanced Editing Techniques,” if you need to review this technique.)
6. Using the Move tool, drag one of the animals into the poster image window, then resize and position it to fill the space nicely (see Figure 9.14).
   

   Figure 9.14. With each animal occupying its own layer, you can show and hide them to create different versions of the poster.

   

7. Click the eye icon next to the animal layer in the poster image to hide it, then use the Move tool to drag the other animal into the poster and resize it as needed.
8. Click one of the animal layers and then click the New Fill or Adjustment Layer button to create a Posterize adjustment layer. In the Adjustments panel, set the number of colors to 2.
9. Alt-click the border between the animal layer and the new adjustment layer to restrict the adjustment layer’s effects to the boundaries of the animal layer (see Figure 9.15).
   

   Figure 9.15. The adjustment layer is indented in the Layers panel, showing that it’s masked by the layer below it.

   

10. Drag the adjustment layer to the New Layer button at the bottom of the panel to duplicate the layer, then move it above the other animal layer. Repeat step 9 with this second adjustment layer.
11. Click the eye icons next to the different animal layers in turn to show the two different versions of the poster. Now that the poster’s complete, you can print the different versions, save them in a different format for use in page layout, or export them to a Web format.

Working with Transparency

Each pixel on a layer (other than the Background layer) has an opacity that’s determined by the Opacity value set for the tool you used to create that pixel. Copied and pasted pixels retain their opacity levels in their new locations. Each layer also has an opacity value, set at the top of the Layer panel. These two values combine to determine the overall opacity of each pixel. For instance, if you paint on a layer with the Brush’s opacity set to 50%, you set the layer itself to 50% opacity, the painting you did now has an effective opacity of 25% to 50% of 50% (see Figure 9.16). (The variation occurs because you can paint over a particular spot more than once, giving it a higher opacity.) Because of this variable transparency, you can combine layers in an infinite number of ways that could never be achieved with traditional art tools.

Figure 9.16. The foreground color swatch shows the true intensity of the orange paint applied here. It’s reduced by 25% opacity because both the Brush and the layer are set to 50% opacity.

The Layers panel’s Opacity control is an odd beastie that can function two ways. First, obviously, you can enter a numeric percentage in the text entry field. Second, you can click the triangle next to the entry field to bring up a pop-up slider that runs from 0% to 100%.

Erasing to Transparency

As you know, when you use the Eraser on the Background layer, it erases to the background color. On a regular layer, however, the Eraser erases to transparency instead. When you create a new layer by clicking the New Layer button, that layer is completely transparent; its opacity value is zero. And if you select all on a nontransparent layer and then press Delete, that layer is then completely transparent. The point here is that under each pixel on a layer lies transparency. When you erase or select and delete a pixel, you’ll be able to see through that space to what lies underneath. And, like the Brush and other painting tools, the Eraser has an opacity setting that determines just how much it erases. At values below 100%, it leaves behind some amount of the color rather than erasing to complete transparency.

Protecting Transparent Pixels

You can lock a layer’s transparency so that you won’t be able to paint over it. When you paint on that layer or fill a selection when the layer is active, the new color only “sticks” to nontransparent pixels. To lock transparency, click the layer to select it in the Layer panel and then click the Lock Transparent Pixels button at the bottom of the panel (see Figure 9.17). A lock icon appears next to the layer’s name to indicate that its transparency is locked. You can paint on the layer or use the Edit menu’s Fill Layer command to fill it with color, but your changes will only affect any pixels that are already colored.

Figure 9.17. With the layer’s transparency locked, the purple only fills nontransparent parts of the layer within the selection.

LET ME TRY IT

Modifying Layer Transparency

Here’s a neat way to use transparent layers to achieve a timeless, faraway effect. You’ll combine a layer containing the original image with another containing a blurred version of the image to produce a truly special effect.

1. Choose an image with enough contrast that it’ll still look presentable in black and white and open it in the Editor’s Full Edit mode.
2. Choose Convert to Black and White from the Enhance menu.
3. In the Convert to Black and White dialog, pick the style that works best for your picture. Adjust the effect using the sliders if necessary, then click OK (see Figure 9.18).
   

   Figure 9.18. What you’re aiming for is a decent amount of contrast without harshness.

   

4. In the Layers panel (choose Layers from the Window menu if you don’t see it), drag the Background layer to the New Layer button to duplicate it.
5. Click the duplicate layer in the Layers panel to select it, then choose Gaussian Blur from the Blur submenu of the Filters menu.
6. Drag the Radius slider to apply a blur to the duplicate layer; settings vary depending on the resolution of the image. The goal is to significantly blur the picture without losing all sense of its contents (see Figure 9.19).
   

   Figure 9.19. Don’t be shy with your blurring—you’re going to put the image details back in the next step.

   

7. Again in the Layers panel, change the Opacity value for the blurred layer to 50. You may want to experiment with this setting—a little lower, a little higher—until you’re happy with the final effect (see Figure 9.20).
   

   Figure 9.20. The final image looks soft and old-timey without actually looking blurry.

   

Putting Image Adjustments on Layers

Another way you can keep your options open with layers is to put adjustments on layers rather than applying them directly to the image. That way, you can modify the adjustment settings, reorder the adjustment layer to change which other layers it affects, and of course delete the adjustment layer if you decide you don’t want it after all. In addition, each adjustment layer has its own layer mask; Photoshop Elements includes a layer mask automatically. You can use the mask to confine the effects of the layer’s adjustment to a particular area, or you can just leave it blank so that the adjustment works over the entire layer.

Adjustment layers come in eleven types, the first three of which are technically called fill layers:

• Solid Color—A layer filled with a single color (see Figure 9.21). You can change the color at any time after creating the layer.

Figure 9.21. Fill layers can only contain color, a pattern, or a gradient, and you can’t paint on them.

• Gradient—A layer filled with a gradient. You can choose a different gradient as many times as you want after you create the layer.

• Pattern—A layer filled with one of the built-in repeating patterns.

• Levels—Acts the same as the Levels dialog, adjusting the way the brightness levels within the image relate to each other.

• Brightness/Contrast—Works like the Brightness/Contrast dialog, adjusting the overall lightness and darkness of the image.

• Hue/Saturation—Has the same effect as the Hue/Saturation dialog, enabling you to modify the image’s brightness, color saturation, and overall hue.

• Gradient Map—Changes the colors of the image to match a specified gradient based on how light or dark they are.

• Photo Filter—Applies an adjustment based on one of a set of traditional lens filters that modify the color slightly to warm up, cool down, or clarify the image.

• Invert—Reverses the picture’s colors to create a negative image.

• Threshold—Converts the image to black and white; you specify the brightness level above which pixels turn white and below which pixels turn black.

• Posterize—Reduces the colors in the picture to a number you specify.

LET ME TRY IT

Creating Adjustment Layers

To create a new adjustment layer, follow these steps:

1. In the Layers panel, click to activate the layer above which you want to place the new adjustment layer. The adjustment layer will affect all the layers below it and will be hidden by any nontransparent pixels on layers above it, so its position in the layer stack is very important.
2. Click the New Fill or Adjustment Layer button at the bottom of the Layers panel and choose the adjustment you want from the pop-up menu (see Figure 9.22).
   

   Figure 9.22. After creating an adjustment layer, you can return to it and change the adjustment type and the adjustment settings.

   

3. In the Adjustments panel, make the settings you want to use for the layer. The adjustment layer appears in the Layers panel with a default name that indicates the type of adjustment it holds.
   

   You can change an adjustment layer’s name the same way you would any other layer—by double-clicking its name in the Layers panel and entering a new name. Use names that make sense to you. The names won’t be visible in the final image, so it doesn’t matter whether they’re meaningful to anyone else.

4. To edit the adjustment layer’s mask, paint on the layer with black in areas where you want to block the effect and leave it white in areas where you want the full effect. Any parts of the area you paint gray will have a partial effect (see Figure 9.23).
   

   Figure 9.23. The black areas of the adjustment layer’s mask prevent the adjustment from affecting the grass in the image.

   

   If you want to actually see the layer mask as you’re painting on it, you have two choices. Alt+click to display the mask only; Shift+alt+click to show the mask as a transparent red overlay on the image itself. When you’ve finished, Alt+click or Shift+Alt+click to hide the mask again, or just click another layer in the Layers panel. It doesn’t matter which way you view the layer mask when you’re editing it; your changes have the same effect either way.

5. If you want to change the adjustment settings for the layer, double-click the layer’s icon in the Layers panel to display its settings in the Adjustments panel. Make any changes you want; if the Preview box in the dialog is checked, you’ll see the changes reflected in the image as you make them. When you’ve finished, just switch to another layer or tool, close the Adjustments panel, or choose a new command.

When you want to see the image without an adjustment layer’s effects, you can simply click the visibility icon next to its entry in the Layers panel to hide it. Deleting it works the same way as deleting any other layer; just drag the adjustment layer to the Delete Layer button at the bottom of the Layers panel.

Lining Layers Up with Guides and the Grid

When your picture is made up of objects floating around on their own layers, you’ll need a way to make sure that those objects are positioned the way you want them with respect to the other layers. The Editor offers you two very helpful tools for making this happen: guides and the grid. Both are made up of straight lines that show up in Photoshop Elements, but not in the printed picture, when you open the image in another program, or when it’s displayed on a web page.

To make the grid visible, choose Grid from the View menu. Fine gray lines, similar to those on a sheet of graph paper, appear over the picture (see Figure 9.24). You can use them as is, to eyeball object placement within the image window, or you can kick things up a notch by making the gridlines sticky, so that objects moved within a few pixels of them automatically snap to the lines. Choose Grid from the Snap To submenu in the View menu to accomplish this; anytime Grid has a check next to it, objects you move around when the grid is visible will gravitate to nearby gridlines. When you want to hide the grid, just choose Grid from the View menu again.

Figure 9.24. The distance between gridlines can be modified in the preferences.

Guides work the same way gridlines do, except that you can add guides wherever you want them within the image window. Cool, huh? That’s why Photoshop Elements users have been begging Adobe to add guides to the Editor for years, and why Adobe finally listened with the development of version 8. There are two ways to create a guide.

First, if the rulers are displayed along the image window’s edges (choose Rulers from the View menu), you can click a ruler and drag down or across to drag a guide into the window. Guides automatically snap to the edges of any content on the current layer, so you can add a guide along the side of an object and then switch to another layer to move that layer’s content over to the guide. If Snap to Guides is turned on in the View menu, objects you move snap to the nearest guide.

Second, whether or not the rulers are visible, you can choose the New Guide command from the View menu and enter a numeric position to create a guide at a specific location (see Figure 9.25). First choose an orientation for the guide—horizontal or vertical—and then enter the position you want, as measured from either the left or the top of the image window, respectively. Click OK, and the guide appears in the window. You can relocate it, using the Move tool, if you decide you want it elsewhere. Or, if you don’t want it to move at all, you can choose Lock Guides from the View menu to prevent all guides from changing positions.

Figure 9.25. Guides can be dropped in manually or placed precisely by the measurements.

You can control the color and style of guides and gridlines in the Editor’s preferences. In the Preferences dialog, choose Guides & Grid.